Soft tissue tumor


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Soft tissue tumor

  1. 1. Soft tissue tumor Dr NARMADA PRASAD TIWARI
  2. 2. • Soft tissue is defined as complex of nonepithelial extra skeletal structure of body exclusive of supportive tissue of various organs and the hematopoietic/ lymphoid tissue.
  3. 3. • It is composed of fibrous tissue, adipose tissue, skeletal muscle, blood and lymph vessels and peripheral nerve. • Most of the soft tissue derived from mesoderm with neuroectodermal contribution corresponding to peripheral nerve.
  4. 4. Pathogenesis • Unknown • Radiation therapy • Chemical burn, thermal burn • Trauma • HHV-8 – kaposi sarcoma • GENETIC SYNDROME- • NEUROFIBROMATOSIS –NEUROFIBROMA,MALIGNANT PHERIPHERAL NERVE SHEATH TUMOUR • Gardner syndrome- fibromatosis • Li- fraumeni syndroma- soft tissue sarcoma • Oslar –weber rendu syndrome-telengiectasia
  5. 5. • Mutation in the mesenchymal stem cells • Speciic chromosomal abnormality-
  6. 6. Cytogenetics • Ewing’s tumor/PNET t(11;22) • Myxoid liposarcoma t(12;16) • Clear-cell sarcoma t(12;22) • Alv. rhabdomyosarcoma t(2;13) or t(1;13) • Congenital fibrosarcoma t(12;15) • DFSP t(17;22) • Synovial sarcoma t(X;18)
  7. 7. Cytologic Features Nuclear Characteristics Cell Type Serpiginous Peripheral nerve sheath tumors Cigar-shaped Smooth muscle tumors Elongated fusiform (Myo-)fibroblastic tumors Uniform, fusiform, & “blue” Synovial sarcoma Pseudoinclusions Neural tumors Cytoplasmic Features Cell Type Fibrillary Myogenous-striated or smooth Vacuolated Myogenous-smooth Cross striations Myogenous-striated Granular & eosinophilic Granular cell tumors; some smooth muscle tumors
  8. 8. Fascicular Growth • Leiomyosarcoma • Nodular Fasciitis • Fibromatosis • Solitary Fibrous Tumor • Peripheral nerve sheath tumors
  9. 9. “Herringbone” Tumors • Synovial sarcoma • Neurofibrosarcoma • Solitary Fibrous Tumor
  10. 10. Storiform Growth • Malignant fibrous histiocytoma • Dermatofibrosarcoma protuberans (DFSP) (best representative of this group) • Other fibrohistiocytic tumors • Occasional leiomyosarcomas • Some examples of malignant peripheral nerve sheath tumor • Occasional synovial sarcomas • Solitary fibrous tumor
  11. 11. Starry Night - Vincent VanGogh Storiform Pattern
  12. 12. DFSP
  13. 13. Location • 40%- lower extremity specially Thigh. • 30%- trunk and retro peritoneum. • 10%- upper extremity. • 10% - head and neck. • Males are affected more than females(1.4 : 1) • Incidence – increases with age
  14. 14. Superficial Deep Atypical MFH fibroxanthoma Atypical Liposarcoma lipoma EFFECT OF TUMOR DEPTH: SAME PATTERN BUT DIFFERENT DIAGNOSIS
  15. 15. • Specific sarcoma tend to be occur in certain age group – • Children- Rhabdomyosarcoma , • Young adulthood- synovial sarcoma • Middle to Late adult life- liposarcoma ,fibrosarcoma.
  16. 16. Classification • TUMORS OF ADIPOSE TISSUE - Lipoma - Liposarcoma • TUMOR OF FIBROUS TISSUE - Nodular fasciitis - Fibromatoses - Fibrosarcoma • FIBROHISTIOCYTIC TUMOR - Fibrous histiocytoma -Dermatofibrosarcoma protuberance - Malignant Fibrous Histicytoma • SKELETAL MUSCLE TUMOR - Rhabdomyoma - Rhabdomyosarcoma
  17. 17. • SMOOTH MUSCLE TUMORS -Leiomyoma -Leiomyosarcoma • VASCULAR TUMORS -Hemangioma -Lymphangioma -Hemangioendothelioma -Hemangiopericytoma -Angiosarcoma
  18. 18. • PERIPHERAL NERVE TUMORS -Neurofibroma -Schwanoma -Granular cell tumor -Malignant peripheral nerve sheath tumors • TUMORS OF UNCERTAIN HISTIOGENESIS -Synovial sarcoma -Epitheloid sarcoma
  19. 19. French Federation Grading System Of Sarcoma Tumor Differentiation • Score 1: Sarcoma closely resembling normal adult mesenchymal tissue Ex- Well differentiated liposarcoma • Score 2: Sarcoma for which hitological typing is certain Ex- Biphasic synovial sarcoma, Alveolar soft part sarcoma • Score 3: Embryonal sarcoma, Undifferentiated sarcoma and sarcoma of doubtfull tumor type
  20. 20. French Federation Grading System Of Sarcoma Mitosis Index • Score 1: 0 to 9 mitoses per 10 fields • Score 2: 10 to 19 mitoses per 10 fields • Score 3: More than 20 mitoses per 10 fields :
  21. 21. French Federation Grading System Of Sarcoma Tumor Necrosis • Score 0: No necrosis • Score 1: < 50 % Tumor necrosis for all the examined tumor surface • Score 2: Tumor necrosis on more than half of the examined tumor surface
  22. 22. French Federation Grading System Of Sarcoma Grading • Grade 1: 2 or 3 • Grade 2: 4 or 5 • Grade 3: Represent a total of 6, 7 or 8
  23. 23. Enneking Staging System For Soft Tissue Sarcoma • Stage 1: G1 Without metastases T1 G1 Without metastases T2 • Stage 2: G2 Without metastases T1 G2 Without metastases T2 • Stage 3 : G1 orG2 With metastases T1 G1 orG2 With metastases T2
  24. 24. Pseudosarcoma • Reactive pseudoarcomatous proliferations are non neoplastic lesions that either develop in response to trauma or idiopathic. • Clinically they are alarming because they develop suddenly and grow rapidly. • Example include • Nodular fascitis • Proliferative fascitis • Proliferative myositis • Myositis ossificans • Pyogenic granuloma
  25. 25. Nodular fascitis • Most common pseudosarcoma • Most often occur in adults and volar aspect of forearm. • Gross – several centimeters in diameter , nodular configuration, poorly defined margins. • Microscopy –richly cellular ,plump immature appearing fibroblast. • A feature of diagnostic significance is the presence of undulating wide bands of collagen lined on the sides by spindle cells.
  26. 26. Nodular fascitis
  27. 27. Collagen deposition in nodular fasciitis
  28. 28. Calcifying aponeurotic fibroma • Hand or wrist of a child or adolescent • it may appear as a nodule or as an ill-defined infiltrating mass in the subcutaneous tissue or attached to a tendon • Microscopic- the lesion is characterized by a diffuse fibroblastic growth in which spotty calcification occurs. Infiltration of fat and striated muscle is often seen at the periphery. Mitoses are scarce, and atypical cytologic features are absent. Scattered osteoclast-like giant cells are frequently seen.
  29. 29. Calcifying aponeurotic fibroma
  30. 30. Proliferative myositis • The skeletal muscles of the shoulder, thorax, and thigh are those most commonly affected. • Most patients are over the age of 45 years • Gross- ill defined scar-like indurations of the muscle . • Microscopic-a cellular proliferation rich in fibroblasts is seen surrounding individual fibers. The hallmark of the lesion is the presence of very large basophilic cells with vesicular nuclei and very prominent nucleoli.
  31. 31. Proliferative myositis
  32. 32. Myositis ossificans • It is a reactive condition that is sometimes mistaken microscopically for osteosarcoma. • The term is inaccurate because the muscle may not be involved, and inflammation is virtually absent. • A history of trauma is obtained in only half of the patients. • The most common locations are the flexor muscles of the upper arm (especially the brachialis anticus), the quadriceps femoris, the adductor muscles of the thigh, the gluteal muscles,
  33. 33. • Microscopic- there is a highly cellular stroma associated with new bone and, less commonly, cartilage formation. • In an early lesion, the centrally placed areas may be very difficult to distinguish from osteosarcoma because of their extreme cellularity. • The most important diagnostic feature is provided by the maturation pattern (‘zonal phenomenon’), characterized by a central cellular area, an intermediate zone of osteoid formation, and a peripheral shell of highly organized bone
  34. 34. Various appearances of myositis ossificans. A, Deep region showing a highly cellular appearance that can simulate a soft tissue sarcoma. B, Midportion showing osteoid formation by plump osteoblasts. C, Peripheral portion showing a shell of well-formed bone
  35. 35. Elastofibroma Almost exclusively the subscapular region of elderly individuals There is often a history of strenuous manual labor. Microscopic-collagen bundles alternate with numerous acidophilic, refractive cylinders often containing a central dense core, both of which stain strongly with elastic stains. Ultrastructurally- the cylinders are made up of immature amorphous elastic tissue, whereas the central core contains mature fibers. Elastase digestion fully removes this material. Immunohistochemically- the cells present in the lesion are positive for CD34, MEF-2, prominin 2 (CD133), and factor XIIIa
  36. 36. Elastofibroma
  37. 37. Fibromatosis 1 Proliferation of well-differentiated fibroblasts 2 Infiltrative pattern of growth 3 Presence of a variable (but usually abundant) amount of collagen between the proliferating cells 4 Lack of cytologic features of malignancy 5 Scanty or absent mitotic activity 6 Aggressive clinical behavior characterized by repeated local recurrences but lack of capacity to metastasize distantly
  38. 38. • Grossly, these lesions are often large, firm, and whitish, with ill-defined outlines and an irregularly whorled cut surface. They often arise in a muscular fascia. • Microscopically, most of the proliferating cells have features intermediate between those of fibroblasts and smooth muscle cells
  39. 39. Fibromatosis The spindle cells of fibromatosis grow diffusely between skeletal muscle fibers
  40. 40. Fibrosarcomas Common tumors of adults, although they can occur in any age group and even be present as congenital neoplasms. Fibrosarcomas can arise from superficial and deep connective tissues such as fascia, tendon, periosteum, and scar; grow slowly or rapidly; and often appear well circumscribed. They usually are soft and cellular and may contain areas of necrosis and hemorrhage
  41. 41. • Microscopic- The cells are arranged in fascicles that intersect each other at acute angles, resulting in a herringbone appearance. • The individual cells resemble normal fibroblasts, and a reticulin stain demonstrates abundant fibers wrapped around each cell. • It should be differented from monophasic synovial sarcoma, liposarcoma, malignant fibrous histiocytoma, and MPNST.
  42. 42. • Immunohistochemically the prototypical fibrosarcoma should have reactivity for vimentin and type I collagen but not for smooth muscle markers, histiocytic markers, or basal lamina components
  43. 43. Fibrosarcoma
  44. 44. Congenital fibrosarcoma (infantile fibrosarcoma) • is an extremely cellular tumor characterized by very rapid growth and the capability for extensive local invasion, but its metastatic rate is negligible. • At the molecular level, it is characterized by the ETV6–NTRK3 gene fusion, which results from the chromosomal translocation t(12;15)(p13;q25)
  45. 45. Congenital fibrosarcoma. The tumor is extremely cellular and mitotically active
  46. 46. Sclerosing epithelioid fibrosarcoma • It is a variant of fibrosarcoma ,It is composed of small, round to ovoid tumor cells embedded in a dense fibrohyaline stroma. • The scanty cytoplasm often has a clear appearance, and there may be an Indian file pattern of growth . Necrosis and bone invasion may be found. • There is consistent positivity for vimentin, and occasional positivity for EMA and even for keratin. • The tumor is associated with a high incidence of local recurrence and distant metastases
  47. 47. Schlerosing epitheloid FS
  48. 48. Inflammatory Myofibroblastic Tumor • Which blends imperceptibly with cases that have been reported as inflammatory pseudotumor on one hand and inflammatory fibrosarcoma on the other. • Many of the cases have occurred in the mesentery or retroperitoneum of children or adolescents
  49. 49. Inflammatory myofibroblastic tumor .
  51. 51. Benign Fibrous Histiocytoma • Dermatofibroma • Tenosynovial giant cell tumor • Pigmented villonodular synovitis The microscopic- A variable mixture of histiocyte- like cells (some foamy, others multinucleated, still others containing hemosiderin) and fibroblast- like cells is always present. Some lesions can be extremely cellular (cellular variant), and some may have large atypical nuclei (atypical variant),
  52. 52. Tenosynovial giant cell tumor. A polymorphic infiltrate of small histiocytes and multinucleated giant cells is embedded in dense fibrous tissue
  53. 53. Intermediate (borderline) fibrous histiocytoma • This vaguely defined group of tumors is characterized by local aggressiveness but an extremely low rate of distant metastases. • Dermatofibrosarcoma protuberans (DFSP)- • It is typically centered in the dermis, but it can also occur in deeper soft tissues. • Microscopically - lack of circumscription; high cellularity; a relatively monomorphic appearance; nuclear hyperchromasia; moderate to high mitotic activity; lack or inconspicuousness of giant, foamy, or hemosiderin-laden cells; and the presence of what has been called a storiform pattern of growth . • This refers to a peculiar arrangement of the tumor cells around a central point, producing radiating ‘spokes’ grouped at right angles to each other.
  54. 54. • dermatofibrosarcoma protuberans have a translocation that involves chromosomes 17 and 22
  55. 55. DermatofibroSaroma
  56. 56. Pigmented dermatofibrosarcoma (Bednar tumor) • looks like the usual dermatofibrosarcoma protuberans except for the presence of a population of dendritic cells heavily loaded with melanin.
  57. 57. Malignant Fibrous Histiocytoma • Several morphologic variants of MFH have been described. • Storiform-pleomorphic MFH is the prototypic and most common member of this group. • Most cases occur in the deep soft tissues of extremities in adults, with a peak in the seventh decade, but cases have also been recorded in children. • Some develop at the site of previous radiation therapy. • Still others have appeared around an infarct or a foreign body or at the site of a surgical scar.
  58. 58. Malignant Fibrous Histiocytoma • Microscopic features - the presence of highly pleomorphic tumor cells and a storiform pattern of growth. • Sometimes the cytoplasm of the giant tumor cells is seen to contain numerous variably sized hyaline globules, thought to be related to apoptosis and lugubriously called thanatosomes. • Inflammatory elements, such as lymphocytes, plasma cells, and eosinophils, are usually mixed with the neoplastic cells. • Metaplastic bone and cartilage formation may be present focally
  59. 59. • Immunohistochemically, there is usually reactivity for vimentin, a1-antitrypsin, a1- antichymotrypsin, KP-1 (CD68), factor XIIIa, ferritin, and the plasma proenzyme factor XIII.
  60. 60. Malignant Fibrous Histiocytoma
  61. 61. MYXO FIBROSARCOMA • is the term currently preferred for the tumor also known as myxoid MFH • Most of these tumors arise in the extremities of adults. • Grossly, they are mucoid and resemble myxoid liposarcomas . • Microscopically, the low-grade forms exhibit an abundant matrix of acid mucopolysaccharides, high vascularity, and the presence of cells resembling lipoblasts. • They are distinguished from myxoid liposarcomas by the presence elsewhere in the tumor of typical areas with the storiform–pleomorphic MFH pattern and the absence of true lipoblasts.
  63. 63. Low-grade fibromyxoid sarcoma (Evans tumor) • Usually deep but sometimes superficial, especially in children • Characterized by alternating fibrous and myxoid areas, a focally whorled pattern of growth, low cellularity, and a bland appearance of the fibroblastic spindle cells[ • The main differential diagnosis is with myxofibrosarcoma. Low-grade fibromyxoid sarcoma has a biphasic fibrous and myxoid appearance, and the vascular network is less well developed.
  64. 64. Low-grade fibromyxoid sarcoma (Evans tumor) MYXO FIBROSARCOMA
  65. 65. hyalinizing spindle cell tumor with giant rosettes • Morphologic variant of low-grade fibromyxoid sarcoma characterized by the presence of huge rosettelike formations made up of hyalinized collagen • t(7;16)(q33;p11).
  66. 66. Hyalinizing spindle cell tumor with giant rosettes
  67. 67. Inflammatory myxohyaline tumor • low-grade malignant tumor usually found in the distal extremities . • Microscopically, it has an infiltrative multinodular quality and a polymorphic cellular composition in a hyaline or myxoid background . • There is a dense mononuclear inflammatory infiltrate containing scattered stromal cells of either epithelioid or spindle shape. Some of the latter are very large, with bizarre nuclei and prominent nucleoli, resulting in a resemblance to Reed–Sternberg cells or virus-infected cells. • The immunohistochemical profile, which is nonspecific, includes occasional focal reactivity for keratin. Local recurrence is common, but distant metastases are exceptional.Recently, this neoplasm is shown to exhibit a recurrent genetic aberration t(1;10)(p22;q24),
  68. 68. Inflammatory myxohyaline tumor
  69. 69. Inflammatory MFH • The neoplastic cells are mixed with, and even obscured by, an intense inflammatory infiltrate rich in neutrophils. • Some of the tumor cells contain phagocytosed neutrophils in their cytoplasm. Storiform pattern, collections of foamy cells, and areas of tissue necrosis are also consistently present
  70. 70. Inflammatory MFH
  71. 71. Plexiform fibrohistiocytic tumor • occurs chiefly in children and young adults. • It usually presents as a small, slow-growing dermal or subcutaneous mass, often in an upper extremity. • Microscopically, there is a multinodular or plexiform proliferation of fibroblast-like and histiocyte-like cells admixed with osteoclast-like giant cells. • They have been divided morphologically into three subtypes: • fibroblastic, • histiocytic (often with osteoclast-type giant cells), • and mixed.
  72. 72. Plexiform fibrohistiocytic tumor
  73. 73. Angiomatoid MFH • extremities of children and young adults as a circumscribed, multinodular, or multicystic hemorrhagic mass. • Microscopically, highly cellular foci are mixed with focal areas of hemorrhagic cyst-like spaces and large aggregates of chronic inflammatory cells. The latter are often arranged at the periphery of the tumor in the form of lymphoid follicles and may simulate the appearance of a lymph node.
  74. 74. Angiomatoid MFH
  75. 75. Tumors of peripheral nerves
  76. 76. • Proliferative lesions of peripheral nerves are divided into • Non-neoplastic - traumatic neuroma. • Benign tumors - schwannomas, neurofibromas, and perineuriomas. • Malignant tumors-malignant peripheral nerve sheath tumors (MPNSTs)
  77. 77. Neuroma The large majority of neuromas follow trauma – hence their designation as traumatic neuromas. Amputation neuroma, a term made popular during the First World War, is a type of traumatic neuroma in which the original trauma involves the loss of part or all of an extremity This lesion may be exquisitely painful Microscopically, all the elements of a nerve can be recognized: axons, Schwann cells, perineurial cells, and fibroblasts In addition, scar tissue is often present. Immunohistochemically, the Schwann cells of traumatic neuroma show CD68 and Ki-M1-P.
  78. 78. Neuroma
  79. 79. Schwannoma (neurilemoma) • Truly encapsulated neoplasms • Almost always solitary • Its most common locations are the flexor surfaces of the extremities, neck, mediastinum, retroperitoneum, posterior spinal roots, and cerebellopontine angle. • The nerve of origin often can be demonstrated in the periphery, flattened along the capsule but not penetrating the substance of the tumor . • Since this is a benign neoplasm that only rarely recurs . • The great majority of cases occur sporadically. • A small percentage of cases are associated with neurofibromatosis type 2 (caused by a germline mutation in the NF2 gene located on 22q12, which encodes merlin, also known as schwannomin
  80. 80. Schwannoma
  81. 81. • immunoreactivity for S-100 protein, calretinin (in contrast to neurofibromas), calcineurin, basal lamina components ,vimentin, nerve growth factor receptor, lipocortin-1, and sometimes glial fibrillary acidic protein and KP-l • Palisading of nuclei is not unique to schwannoma. • It can also occur in leiomyoma, leiomyosarcoma, • GIST, • calcifying aponeurotic fibroma, • non-neoplastic smooth muscle • (most commonly in the appendiceal wall).
  82. 82. Cellular schwannoma • It is the term used for highly cellular schwannomas that are exclusively composed of Antoni A areas but lack Verocay bodies. • These changes can be accompanied by nuclear atypia, mitotic activity, and focal necrosis. • Most reported cases have been in the retroperitoneum, pelvis, and mediastinum
  83. 83. Cellular schwannoma
  84. 84. Psammomatous melanotic schwannoma • Most arise from the spinal nerve roots. • Microscopically by the presence of melanin pigmentation and the deposition of psammoma bodies . • In contrast to all other types of schwannoma described in this section, the psammomatous melanotic variety is regarded as a low-grade malignancy because of its tendency for local recurrence and the fact that a few of the reported cases have metastasized
  85. 85. Psammomatous melanotic schwannoma
  86. 86. Neurofibroma • The gross appearance of -As a rule, the tumors are not encapsulated and have a softer consistency than schwannoma . • The more superficial tumors appear as small, soft, pedunculated nodules protruding from the skin (‘molluscum pendulum’). • Deeper tumors grow larger. Tumors resulting in diffuse tortuous enlargement of peripheral nerves are designated as plexiform neurofibromas and are usually seen in the context of type 1 neurofibromatosis (caused by a germline mutation in the NF1 gene located on 17q11.2, which encodes neurofibromin).
  87. 87. Neurofibroma Well-circumscribed neurofibroma of soft tissue. The tumor has a gelatinous appearance Typical gross appearance of plexiform neurofibroma. This tumor variety is indicative of Recklinghausen disease
  88. 88. Neurofibroma • Microscopic- Neurofibromas are formed by a combined proliferation of all the elements of a peripheral nerve: axons, Schwann cells, fibroblasts, perineurial cells . • Axons can be demonstrated by silver or acetylcholinesterase stains or by immunostaining for neuron-specific enolase (NSE), neurofilaments, or various neuropeptides. • Schwann cells usually represent the predominant cellular element. Most have markedly elongated nuclei, with a wavy, serpentine configuration and pointed ends. • In contrast to schwannomas, Verocay bodies, palisading of nuclei, and hyaline thickening of the vessel wall are almost always absent in neurofibromas
  89. 89. Neurofibroma
  90. 90. NEUROFIBROMATOSIS - single-gene disorder, autosomal-dominant . Two forms.- - von Recklinghausen disease (neurofibromatosis type 1), patients have multiple café-au-lait spots and dermal neurofibromas. - Neurofibromatosis type 2, patients have predominantly bilateral acoustic neuromas (schwannomas) that are associated with other brain and spinal cord tumors.
  91. 91. • It is diagnosed based on the presence of any two of the following: 1. At least five café-au-lait spots larger than 5 mm (six larger than 15 mm if the patient is prepubertal) 2. Two or more neurofibromas of any type or one plexiform type 3. Multiple large freckles in the axillary or inguinal regions 4. Sphenoid wing dysplasia 5. Bilateral optic nerve gliomas 6. Multiple iris nodules (Lisch spots) 7. A first-degree relative with the preceding criteria
  92. 92. Perineurioma • Benign tumors of the peripheral nerve composed predominantly or exclusively of perineurial cells are being increasingly recognized.Microscopically, they are composed of extremely elongated cells arranged in parallel bundles. • Some cases have a storiform pattern of growth and may correspond to the former storiform perineurial fibromas. • There is an intraneural variant of perineurioma, • Other recently recognized variants of this tumor include sclerosing perineurioma, which has a predilection for the fingers and palms of young adults;[reticular (retiform) perineurioma, with a predominant lace-like or reticular growth pattern composed of anastomosing cords of spindle cells; • plexiform perineurioma;and the exceptionally rare granular cell perineurioma. • Hybrid forms of schwannoma and perineurioma have also been described, • as well as malignant forms of perineurioma, the latter representing a subtype of MPNST
  93. 93. Perineurioma
  94. 94. Malignant peripheral nerve sheath tumor • It is the currently preferred term for the neoplasm also known over the years as malignant schwannoma, neurogenic sarcoma, and neurofibrosarcoma. • Approximately half of these tumors arise de novo. • The other half from nerves involved by neurofibromas as part of type 1 Recklinghausen disease. • Some have occurred in areas of previous irradiation.
  95. 95. Malignant peripheral nerve sheath tumor • Because of its difficult microscopic recognition, errors are often made. • There are two circumstances in which the diagnosis of MPNST should be the primary consideration in the presence of a malignant tumor of soft tissues composed of spindle cells: (1) when the tumor develops in a patient with type 1 Recklinghausen disease; • (2) when the tumor is obviously arising within the anatomic compartment of a major nerve or in continuity with a neurofibroma.
  96. 96. Malignant peripheral nerve sheath tumor • In the absence of these circumstances the light microscopic diagnosis of MPNST is • They include: serpentine shape of the tumor cells; • Arrangement in palisades or whorls; • Marked contrast between the deeply hyperchromatic nuclei and the pale cytoplasm (‘punched-out nuclei’); • Perivascular concentration of tumor cells, with a plumper shape; • Epithelioid appearance of the endothelial cells of these vessels; • Presence of large gaping vascular spaces, resulting in a hemangiopericytoma-like appearance; • Geographic areas of necrosis, with tumor palisading at the edges
  97. 97. The contrast between the dark hyperchromatic nuclei and the light cytoplasm is typical of malignant peripheral nerve sheath tumor
  98. 98. Malignant peripheral nerve sheath tumor
  99. 99. Malignant peripheral nerve sheath tumor, Malignant peripheral nerve sheath tumor with skeletal muscle differentiation (so- called ‘triton tumor’). , Positive immunostain for myoglobin
  100. 100. Tumors of adipose tissue
  101. 101. Lipoma • Benign fatty tumors can arise in any location in which fat is normally present. • The majority occur in the upper half of the body, particularly the trunk and neck, but they can develop in any other site, including hands and feet.[ • Most lipomas are subcutaneous, an important point in the differential diagnosis with liposarcomas, which are almost always deep-seated. • However, lipomas can also occur in the deep soft tissues; these are subclassified into intramuscular (most common in the trunk) and intermuscular (most common in the anterior abdominal wall). • Most patients are in the fifth or sixth decade of life • May be single or multiple.
  102. 102. • Lipomas can grow to a large size; • they are usually encapsulated when located in the superficial soft tissues • Poorly circumscribed when arising in deeper structures. • Grossly, lipomas consist of bright yellow fat separated by fine fibrous trabeculae . • Microscopic- they are composed of mature adipose tissue with no cellular atypia. • They are cytologically and immunohistochemically indistinguishable from normal fat, including positivity for S-100 protein and calretinin.
  103. 103. Morphologic variations of lipomas : • 1 Fibrolipoma - characterized by the presence of prominent bundles of mature collagenous or myxocollagenous stroma intermixed with mature adipocytes. It affects mainly the distal extremities. • 2 Myxolipoma. This tumor features focally well- developed myxoid changes. • 3 Chondroid lipoma. This variant is usually deep-seated . It is characterized by a component of eosinophilic and vacuolated cells containing glycogen and lipid that resembles brown fat cells, lipoblasts, and chondroblasts .
  104. 104. • 4- Myolipoma. This tumor is characterized by an admixture in variable proportions of mature adipose tissue and bundles of well-differentiated smooth muscle.[ 5 Spindle cell lipoma.- Characteristically located in the regions of the shoulder and posterior neck of adults, but also found in many other locations, It is composed of an admixture of mature lipocytes and uniform spindle cells set in a mucinous and fibrous background[ Features that assist in distinguishing it from myxoid liposarcoma include the absence of lipoblasts and of a prominent plexiform vascular pattern, the presence of thick (‘ropy’) collagen bundles, and the great uniformity of the proliferating small spindle cells.
  105. 105. • 6 Pleomorphic lipoma. This is a lipoma containing hyperchromatic multinucleated (‘floret-like’) tumor cells within the fibrous septa traversing the neoplasm . • As for spindle cell lipoma, its most common location is the shoulder and posterior neck region. • Differential diagnosis is with the sclerosing form of) well-differentiated liposarcoma (atypical lipomatous tumor). • The location of the lesion is an important clue, • Proportion of floret-type giant cells and lipoblasts is the most important distinguishing feature at the microscopic level..
  106. 106. • 7 Angiolipoma. They are often painful and characteristically multiple. • They are located in the subcutis, most commonly on the trunk or extremities. • Vascularity often is limited to a band of tissue on the periphery of the neoplasm . • Hyaline thrombi are common and constitute an important diagnostic sign[. • The pain correlates well with the degree of vascularity.[
  107. 107. ADIPOSE TM Lipoma
  108. 108. chondroid lipoma Showing admixture of mature fat and chondroid tissue
  109. 109. Spindle cell lipoma The oval to spindle cells are concentrated in the fibrous bands within lobules of mature adipose tissue
  110. 110. Pleomorphic lipoma. The floret cells
  111. 111. Angiolipoma showing Intimate admixture of blood vessels and mature adipose tissue Hyaline thrombi in angiolipoma
  112. 112. Lipoblastoma/lipoblastomatosis • Affects almost exclusively infants and young children (below the age of 5 years). • It commonly involves the proximal portion of the lower and upper extremities. • Grossly, the lesion is soft and lobulated . • It is subdivided into (benign) lipoblastoma (sometimes also designated as embryonal or fetal lipoma) when well circumscribed and • lipoblastomatosis when deep-seated and ill defined. • Microscopic- it closely resembles fetal fat. presence of lipoblasts, a plexiform vascular pattern, and an abundant myxoid stroma .
  113. 113. • It may be confused with myxoid liposarcoma. • It is distinguished from the latter by • virtue of the young age of the patient, • distinct lobulation, • and absence of giant cells or pleomorphic nuclei.
  114. 114. Lipoblastoma
  115. 115. Hibernoma • is a rare benign neoplasm. • Location- interscapular region, axilla, and thigh, but also in the mediastinum and retroperitoneum. • Gross-Its cut surface has a typical brown color, Microscopic- pattern is characteristic – an organoid arrangement of large cells with centrally located nucleus and a cytoplasm filled with many small vacuoles that stain for neutral fat.
  116. 116. hibernoma Gross exhibiting the typical light brown cut surface
  117. 117. Hibernoma.
  118. 118. Liposarcoma • It is the most frequent soft tissue sarcoma in adults. • Liposarcomas are usually large and occur most frequently in the lower extremities (popliteal fossa and medial thigh); retroperitoneal, perirenal, and mesenteric region; and shoulder area. • Grossly, liposarcomas are well circumscribed but not encapsulated. •
  119. 119. lipoblast • The common morphologic denominator of liposarcoma is the lipoblast . • This appears as a mononuclear or multinucleated cell with one or more cytoplasmic vacuoles that contain fat. • The nucleus may be pushed aside by a single large vacuole, resulting in a signet ring configuration, • or it may remain centrally located but exhibit small indentations by multiple small vacuoles. •
  120. 120. Lipoblast
  121. 121. • Enzinger and Winslow divided liposarcomas into four types: • Myxoid, • Round cell, • Well differentiated, • Pleomorphic
  122. 122. Myxoid liposarcoma • Most common type of liposarcoma. • Marked predilection for the lower extremities, particularly the thigh . • It practically never occurs in the retroperitoneum. • Microscopically, myxoid liposarcoma has few or no mitotic figures • and is characterized by proliferating lipoblasts • Prominent anastomosing capillary network, • and a mucoid matrix. • The presence of a delicate network of thin-walled vessels is an important feature in the differential diagnosis with myxoma and other myxoid tumors. •
  123. 123. Myxoid liposarcoma • Cytogenetically, myxoid liposarcoma is characterized by the reciprocal translocation t(12;16)(q13;p11), • t(12;22)(q13;q12)
  124. 124. Myxoid liposarcoma
  125. 125. Round cell type • The tumor cells are small and have a distinctly acidophilic cytoplasm . • The presence among them of scattered lipoblasts establishes the diagnosis. • Mitoses are more and vascular network is less marked than myxoid form.
  126. 126. Round cell liposarcoma
  127. 127. Atypical lipomatous tumor orwell- differentiated liposarcoma • Gross- resembles ordinary lipoma . • It also resembles it on low-power examination, • but closer inspection shows scattered tumor cells with large, deep-staining nuclei. • These atypical cells may concentrate on the fibrous strands that traverse the adipose tissue lobules (sclerosing subtype) • or be scattered among the mature adipocytes (lipoma- like subtype) . •
  128. 128. Atypical lipomatous tumor Sclerosing pattern Lipoma-like subtype of
  129. 129. Pleomorphic liposarcoma • It is a highly cellular, • poorly differentiated neoplasm containing numerous tumor giant cells, • some of them having the features of lipoblasts. • Mitoses • foci of necrosis. •
  130. 130. Pleomorphic liposarcoma Numerous giant lipoblasts
  131. 131. Epithelioid variant of pleomorphic liposarcoma
  132. 132. Dedifferentiated liposarcoma • It is the term used for the emergence of a generally nonlipogenic component within an atypical lipomatous tumor • The dedifferentiated component may already be present at the time of the original excision OR in recurrent or metastatic foci. • It is much more common in retroperitoneal neoplasms. • Microscopic- the dedifferentiated component is usually high grade. • Heterologous elements, such as skeletal muscle (particularly frequent cartilage or blood vessels, may be present
  133. 133. Desmin immunostain Differentiation toward skeletal muscle Dedifferentiated retroperitoneal liposarcoma.
  134. 134. Thank you • To be continued……..
  135. 135. SOFT TISSUE TUMOURS WHO Classification of Soft Tissue Tumour • 1 Adipocytic tumours • Lipoma • Lipomatosis • Lipomatosis of nerve • Lipoblastoma / Lipoblastomatosis • Angiolipoma • Myolipoma of soft tissue • Chondroid lipoma • Spindle cell lipoma • Pleomorphic lipoma • Hibernoma • Atypical lipomatous tumour • Well differentiated liposarcoma • Dedifferentiated liposarcoma • Myxoid liposarcoma • Pleomorphic liposarcoma • Mixed-type liposarcoma • 2 Fibroblastic / Myofibroblastic tumours • Nodular fasciitis • Proliferative fasciitis and proliferative myositis • Myositis ossificans and • fibroosseous pseudotumour of digits • Ischaemic fasciitis • Elastofibroma • Fibrous hamartoma of infancy • Myofibroma / Myofibromatosis • Fibromatosis colli • Juvenile hyaline fibromatosis • Inclusion body fibromatosis • Fibroma of tendon sheath • Desmoplastic fibroblastoma • Mammary-type myofibroblastoma • Calcifying aponeurotic fibroma • Angiomyofibroblastoma
  136. 136. • Cellular angiofibroma • Nuchal-type fibroma • Gardner fibroma • Calcifying fibrous tumour • Giant cell angiofibroma • Superficial fibromatoses • Desmoid-type fibromatoses • Lipofibromatosis • Extrapleural solitary fibrous tumour and • haemangiopericytoma • Inflammatory myofibroblastic tumour • Low grade myofibroblastic sarcoma • Myxoinflammatory fibroblastic sarcoma • Infantile fibrosarcoma • Myxofibrosarcoma • Low grade fibromyxoid sarcoma • Sclerosing epithelioid fibrosarcoma • Adult fibrosarcoma • 3 Fibrohistiocytic tumours • Giant cell tumour of tendon sheath • Diffuse-type giant cell tumour • Deep benign fibrous histiocytoma • Plexiform fibrohistiocytic tumour • Giant cell tumour of soft tissue • Pleomorphic malignant fibrous histiocytoma • Undifferentiated high grade • pleomorphic sarcoma • Giant cell malignant fibrous histiocytoma • Undifferentiated pleomorphic sarcoma • with giant cells • Inflammatory malignant fibrous histiocytoma • Undifferentiated pleomorphic sarcoma • with prominent inflammation
  137. 137. • 4 Smooth muscle tumours • Angioleiomyoma • Leiomyoma of deep soft tissue • Leiomyosarcoma • 5 Pericytic (perivascular) tumours • Glomus tumours • Myopericytoma • 6 Skeletal muscle tumours • Rhabdomyoma • Embryonal rhabdomyosarcoma • Alveolar rhabdomyosarcoma • Pleomorphic rhabdomyosarcoma • 7 Vascular tumours • Haemangiomas • Epithelioid haemangioma • Angiomatosis • Lymphangioma • Kaposiform haemangioendothelioma • Retiform haemangioendothelioma • Papillary intralymphatic angioendothelioma • Composite haemangioendothelioma • Kaposi sarcoma • Other intermediate vascular neoplasms • Epithelioid haemangioendothelioma • Angiosarcoma of soft tissue
  139. 139. Hemangioma • occupy a gray zone between hamartomatous malformations and true neoplasms.. • They are frequently designated and regarded as tumors because of their usually localized nature and mass effect. • However, the fact that they consistently lack chromosomal alterations speaks against a true neoplastic nature. • The presence or absence of nerve bundles intimately admixed with the vascular proliferation has been used to place them into a malformative or a neoplastic category. • A high percentage occurs in children, and many are already present at birth. • Over half of the cases are in the head and neck area; they can also occur in the trunk or extremities. • Most hemangiomas are solitary
  140. 140. Capillary hemangiomas • Made up of small vessels of capillary caliber and can occur in any organ. • Its most common location is the skin, • where it appears as an elevated nodule with an intense crimson color. Such a hemangioma is traditionally known to dermatologists as a strawberry hemangioma because of its clinical appearance. • Microscopic- the lesion exhibits a vaguely lobular configuration on low-power examination . Masses of closely packed spindle cells are seen with neoformed spaces that contain little blood. • Mitotic figures are usually present and can be numerous. At the periphery, the tumor may be seen to invade subcutaneous tissue or skeletal muscle. Perineurial involvement has also been observed. • Mast cells may be numerous.
  141. 141. Capillary hemangioma - showing vaguely lobulated architecture
  142. 142. The high cellularity and mitotic activity should not lead to an overdiagnosis of malignancy
  143. 143. Cavernous hemangiomas • Those occurring in the skin are traditionally known as port-wine nevus or nevus flammeus. • This lesion, which is present at birth, grows very slowly and in proportion to the growth of the patient; in time, it becomes nodular and soft. • In contrast to the strawberry nevus, it does not regress spontaneously. • Are composed of larger vessels with cystically dilated lumina and thin walls
  144. 144. The vascular spaces are widely dilated Cavernous hemangioma
  145. 145. Glomus tumor • Also known as glomangioma, • originates in the neuromyoarterial glomus, a normal arteriovenous shunt abundantly supplied with nerve fibers and fulfilling a temperature-regulating function. • The classic location of the glomus tumor is the subungual region, but it can occur elsewhere in the skin, soft tissues, nasal cavity, and trachea.
  146. 146. • Microscopic- glomus tumors consist of blood vessels lined by normal endothelial cells and surrounded by a solid proliferation of round or cuboidal ‘epithelioid’ cells with perfectly round nuclei and acidophilic cytoplasm . • Immunohistochemically, they manifest reactivity for myosin, vimentin, actin, and basal lamina components but usually not for desmin.
  147. 147. Glomus tumor- The distribution of round glomus cells around the open vascular lumen is a key to the diagnosis
  148. 148. Hemangiopericytoma • This tumor is usually found in the soft tissues of the extremities (usually distal). • Tends to have a multinodular pattern of growth • There is a family of tumor types composed of cells with pericytic features, which blend on one side with vascular smooth muscle cells and on the other with vascular glomus cells. • Presence of branching vessels with a staghorn appearance
  149. 149. Hemangiopericytoma.. Characteristic multinodular quality as seen on low power. High-power view showing a cytologic appearance intermediate between that of glomus cells and pericytes
  150. 150. Hemangioendothelioma • Vascular tumors of an endothelial nature that occupy an intermediate position between the benign hemangioma and the full-blown angiosarcoma.
  151. 151. Hemangioendothelioma
  152. 152. Epithelioid hemangioendothelioma • Is composed of a distinctive type of endothelial cells having an epithelial-like or histiocyte-like appearance. The cytoplasm is abundant and eosinophilic, often vacuolated. The nucleus is round, vesicular, and occasionally indented. Vascular lumina are present, most of them small; some are located intracellularly and are responsible for the cytoplasmic vacuolation
  153. 153. Epithelioid hemangioendothelioma A, The tumor partially fills the lumen of the femoral vein. B, Prominent cytoplasmic vacuolization is apparent on high-power examination of the same case
  154. 154. Malignant endovascular papillary angioendothelioma (Dabska tumor; papillary intralymphatic angioendothelioma) • Is an extremely rare tumor. • Usually seen in children • Located in the skin or soft tissues and • Characterized by papillary tufts that are lined by plump endothelial cells located within dilated vascular lumina, some of which have a glomeruloid configuration. • Many of the tumor cells have epithelioid or histiocytoid features, including cytoplasmic eosinophilia and vacuolation.
  155. 155. Dabska tumor. The papillary configuration of the endothelial fronds can be appreciated
  156. 156. Angiosarcoma • It is usually seen in adults and the elderly. • The most common locations are the skin, soft tissue, breast, bone, liver, and spleen. • Some soft tissue angiosarcomas arise from major vessels, such as the inferior vena cava, pulmonary artery, or aorta. •
  157. 157. • Angiosarcomas have been reported in previously irradiated fields, • Around long-standing foreign bodies, • In arteriovenous fistulas(including surgically constructed ones). • As a secondary somatic-type development in mediastinal or retroperitoneal germ cell tumors, • Arising within preexisting benign tumors, such as hemangioma/vascular malformation, neurofibroma, intramuscular lipoma, or leiomyoma.
  158. 158. • Grossly, angiosarcomas tend to be highly hemorrhagic and deeply invasive • Their microscopic appearance ranges from a pattern so well differentiated as to simulate a benign hemangioma to one so undifferentiated and solid as to simulate carcinoma, malignant melanoma, or other types of sarcoma. • The diagnostic areas of angiosarcoma are represented by the freely anastomosing vascular channels lined by atypical endothelial cells • A pattern that is accentuated by silver reticulin stains or immunostains for basement membrane components. Clusters of reactive lymphocytes and clumps of hemosiderin are common.
  159. 159. • Variations in the appearance of the neoplastic endothelial cells are great. • Their shape ranges from very elongated to plump and epithelioid, and their size from small to giant, with occasional development of multinucleated forms. • The latter are sometimes seen to display prominent hyaline globules containing a1- antitrypsin and a1-antichymotrypsin.
  160. 160. Gross hemorrhagic appearance of angiosarcoma in the region of the hip
  161. 161. Angiosarcoma Anastomosing vascular channels. On high power, the channels are seen to be lined by highly atypical endothelial cells
  162. 162. Epithelioid angiosarcoma
  163. 163. • Immunohistochemically -CD31 and FLI-1 are the most reliable. • Epithelioid variant there is coexpression of keratin. • In other cases there is expression of D2-40, suggesting differentiation toward lymph vessel endothelial cells.
  164. 164. Lymphangioma • Most lymphangiomas represent malformations rather than true neoplasms and are thought to result from failure of the lymphatic system to communicate with the venous system. • Three forms exist: capillary, cavernous, and cystic . • The capillary form occurs in the skin, • Whereas the cavernous variety prefers deep soft tissues. • Cystic lymphangioma has been traditionally known as hygroma. • Its most common presentation is in the form of a poorly defined soft tissue mass in the neck of children, usually situated posterior to the sternocleidomastoid muscle and sometimes extending into the mediastinum
  165. 165. Lymphangioma • Microscopically, lymphangioma consists of large lymphatic channels growing in loose connective tissue. A few disorganized bundles of smooth muscle can be present in the wall of the larger channels
  166. 166. Large cystic hygroma in the neck of an 18-month-old infant. Lymphangioma of soft tissue showing dilated spaces lined by flattened endothelium. A scattering of lymphocytes is present in the stroma
  167. 167. Lymphangiosarcoma • It is regarded as the lymph vessel counterpart of angiosarcoma. • The cutaneous lymphangiosarcoma, present clinically as bluish or purple elevations. • They are often multiple, • Microscopically, they show a wide variation of patterns, ranging from solid undifferentiated areas that can simulate carcinoma to others so well differentiated as to be indistinguishable from lymphangioma or lymphangiectasia . • As in the case of (hem)angiosarcoma, the most typical areas are represented by freely anastomosing channels lined by atypical endothelial cells. • immunohistochemical studies have not only documented the presence of endothelial markers such as D2-40.
  168. 168. Stewart–Treves syndrome The diagnosis of lymphangiosarcoma has been made in the presence of malignant vascular tumors superimposed on areas of chronic lymphedema, the prototypical example being the lymphangiosarcoma developing in patients who have had long-standing massive lymphedema after radical mastectomy for breast carcinoma
  169. 169. Amputated upper extremity in a case of post-mastectomy lymphangiosarcoma. lymphangiosarcoma showing an intricate network of neoplastic vessels
  171. 171. Leiomyoma • Several types of leiomyoma exist. • Cutaneous leiomyomas located in the dermis arise from arrectores pilorum muscles; they are characteristically superficial, small, multiple, and grouped. • Genital leiomyomas are solitary tumors that arise from smooth muscle bundles located in the superficial subcutaneous tissue of genital areas and structures that are topographically and functionally related to them, such as the nipple, areola, axilla, scrotum, penis, vulvar labia, and anal skin. • Vascular leiomyomas (angioleiomyomas) arise from the smooth muscle of blood vessels. They occur more frequently in females and are usually located in the soft tissues of the lower limbs.
  172. 172. • Grossly, vascular leiomyomas are yellow or yellowish pink, sharply circumscribed, and fairly firm . • Microscopically, they are made up of intersecting fascicles of smooth muscle cells encircling vascular lumina lined by normal endothelial cells .
  173. 173. Leiomyoma Gross appearance of a soft tissue leiomyoma located in the leg of a child Vascular leiomyoma. The neoplastic smooth muscle cells are clearly related to vessel walls
  174. 174. Leiomyosarcoma • Leiomyosarcoma of soft tissue is relatively rare. • It is typically a tumor of adults and the elderly. • The leiomyosarcomas seen with increasing frequency in immunosuppressed patients (HIV-infected individuals and organ transplant recipients) have been found to be associated with the Epstein–Barr virus[ • Most soft tissue leiomyosarcomas are located in the extremities, but they can occur anywhere, including the head and neck region. • Many arise from the walls of arteries and veins -inferior vena cava, saphenous vein, femoral vein, pulmonary artery, femoral artery, and aorta.
  175. 175. • Grossly, leiomyosarcomas can be as well circumscribed as the leiomyomas but are larger and softer and have a tendency for fresh tumor necrosis, hemorrhage, and cystic degeneration. • Those arising from major vessels can protrude in a polypoid fashion within the lumen or be predominantly intramural.
  176. 176. Leiomyosarcoma Gross appearance of leiomyosarcoma. The central cystic cavity is a common feature. Leiomyosarcoma filling the lumen of the popliteal vein and its branches, as seen on cross section
  177. 177. • Microscopically, the pattern of growth is predominantly fascicular, with the tumor bundles intersecting each other at wide angles. Merging of tumor cells with blood vessel walls is an important diagnostic clue . • In some cases the vascular pattern is particularly prominent, resulting in a hemangiopericytoma-like appearance. • We regard these tumors as the malignant counterpart of vascular leiomyoma and have designated them vascular leiomyosarcomas. • The individual cells have elongated, blunt-ended nuclei and acidophilic fibrillary cytoplasm. • Palisading of nuclei may occur. • Cytoplasmic vacuoles located at both ends of the nucleus, sometimes indenting them, represent another diagnostic clue. •
  178. 178. The intimate relationship of the tumor cells with the vessel walls Leiomyosarcoma
  179. 179. Clear cell (epithelioid) smooth muscle tumors
  181. 181. Rhabdomyoma • Bona fide soft tissue benign tumors of skeletal muscle origin are exceedingly rare. • They can be divided into distinct subtypes, although some overlap exists. • Those known as the adult type are found almost exclusively in the oral cavity and its vicinity in adult. • Microscopically, the cells are well differentiated, large, rounded or polygonal, with abundant acidophilic cytoplasm containing variable amounts of lipid and glycogen. • Some cells have features of ‘spider cells’, Cross striations and intracytoplasmic rod-like (‘jack straw’) inclusions are frequent, and intranuclear inclusions may be seen. • There is no mitotic activity or nuclear atypia. The differential diagnosis includes granular cell tumor, hibernoma, and the peculiar condition known as crystal-storing histiocytosis
  182. 182. • The fetal form of rhabdomyoma is seen almost exclusively in two locations: the head and neck area (particularly the retroauricular area) in children under 3 years of age. • The vulvovaginal region of middle-aged women.[he latter, also referred to as genital rhabdomyoma. • Microscopically, They are very cellular, formed by immature skeletal muscle fibers (some containing cross striations) and primitive mesenchymal cells . Nuclear aberrations are absent, and mitoses are generally rare. • The vulvovaginal cases tend to have a myxoid quality.
  183. 183. Fetal rhabdomyoma
  184. 184. Rhabdomyosarcoma • • There are three major categories of rhabdomyosarcoma: pleomorphic, embryonal, and alveolar. • Pleomorphic rhabdomyosarcoma.-This tumor, which constituted practically all the cases of rhabdomyosarcoma in the older literature, is actually the least common of the three categories. • It arises in areas where myotome-derived skeletal muscle occurs and is therefore usually located in an extremity, especially the thigh.It occurs almost exclusively in adults, • Grossly, it may be confined within fascial compartments and have the shape of the muscle from which it arises. • Microscopically, the tumor is very pleomorphic, with numerous tumor giant cells. • Making a differential diagnosis with pleomorphic liposarcoma and other types of pleomorphic sarcoma is so difficult that a diagnosis of pleomorphic rhabdomyosarcoma should not be made unless there is incontrovertible evidence of skeletal muscle differentiation in the form of cross striations.
  185. 185. • One should be very careful to avoid the following pitfalls: • (1) entrapped non-neoplastic skeletal muscle fibers; • (2) release of myoglobin from necrotic muscle with subsequent nonspecific absorption by tumor cells, which thus become immunoreactive. • (3) presence of skeletal muscle differentiation in other malignant tumors. •
  186. 186. Pleomorphic rhabdomyosarcoma. The tumor was immunoreactive for desmin and skeletal muscle actin
  187. 187. Embryonal rhabdomyosarcoma. • This tumor type is common in the head and neck region), retroperitoneum, bile ducts, and urogenital tract. • The large majority occur in children between the ages of 3 and 12 years. • Grossly, the tumor is poorly circumscribed, white, and soft.
  188. 188. • Microscopically, the tumor cells are small and spindle shaped. Some have a deeply acidophilic cytoplasm . A feature of diagnostic value is the presence of highly cellular areas usually surrounding blood vessels, alternating with paucicellular regions that have abundant myxoid intercellular material. • Cross striations may or may not be present;
  189. 189. Embryonal rhabdomyosarcoma. Most of the nuclei are oval; the cytoplasm is scanty and acidophilic
  190. 190. Embryonal rhabdomyosarcoma composed predominantly of round cells. There is a perivascular pseudorosette around a blood vessel
  191. 191. Sarcoma botryoides • When growing beneath a mucosal membrane, such as the vagina, urinary bladder, or nasal cavity, it frequently forms large polypoid masses resembling a bunch of grapes – hence the name sarcoma botryoides. • A highly characteristic feature of these polypoid (‘botryoid’) tumors is the presence of a dense zone of undifferentiated tumor cells immediately beneath the epithelium, a formation known as Nicholson cambium layer
  192. 192. Botryoid rhabdomyosarcoma of common bile duct showing a concentration of tumor cells immediately beneath the epithelium (‘cambium layer’).
  193. 193. Alveolar rhabdomyosarcoma • it predominates in an older age group -10–25 years. • and occurs more frequently in the extremities, the most common locations being forearms, arms, and perirectal and perineal regions. • It also occurs in the head and neck region.
  194. 194. • Microscopically, small, round, or oval tumor cells are seen separated in nests by connective tissue septa . • The tumor cells in contact with these fibrous strands remain firmly attached to them, but the others tend to detach because of a lack of cohesiveness, which results in a typical alveolar or pseudoglandular appearance. • The deep acidophilia of the cytoplasm and the presence of occasional multinucleated giant cells are important diagnostic features. • Cases in which the alveolar pattern is poorly developed are referred to as the ‘solid’ variant of alveolar rhabdomyosarcoma and are particularly difficult to diagnose. Before identification of this entity, • Many of these tumors were misdiagnosed as primary malignant lymphoma (of the soft tissues..
  195. 195. Alveolar rhabdomyosarcoma Gross appearance of alveolar rhabdomyosarcoma. The tumor is embedded within skeletal muscle Typical low-power appearance of alveolar rhabdomyosarcoma. Note the small size of the tumor cells.
  196. 196. Synovial sarcoma • Typically arises about the knee and ankle joints of children and young adults. • It also occurs around other joints, such as shoulder and hip. • Grossly, it tends to be well-circumscribed, firm, and grayish pink. • Microscopically, the classic form of synovial sarcoma is that of a biphasic tumor composed of sharply segregated epithelial and sarcomatous components (the terms being used descriptively and not histogenetically) • The epithelial areas usually appear in the form of gland-like spaces lined by cuboidal (synovial-like) or columnar cells, but can also present as solid nests of large pale cells. It is exceptional for this component to exhibit squamous features
  197. 197. • The sarcomatous component is made up of spindle cells with a fibroblast-like appearance. It tends to be hypercellular but with a relatively monotonous appearance, plump nuclei, a focally whorled pattern, distinct lobulation or fasciculation.
  198. 198. Typical biphasic appearance of synovial sarcoma
  199. 199. Synovial sarcoma -with an adenocarcinoma-like appearance of the epithelial component
  200. 200. Monophasic synovial sarcoma • It is composed of only one of the two components. • In the large majority of cases, this applies to the spindle cell sarcomatous component, which is easily misdiagnosed as fibrosarcoma, hemangiopericytoma. • A search for epithelial-looking foci should be carried out in these situations, as well as a thorough immunohistochemical and • possibly molecular evaluation
  201. 201. Monophasic synovial sarcoma
  202. 202. Granular cell tumor • The classic location of tumor, is the tongue, known as granular cell myoblastoma,. • Other locations- skin, vulva, breast, larynx, bronchus, esophagus, stomach, appendix, rectum, anus, salivary glands, bile ducts, pancreas, urinary bladder, uterus, brain, pituitary gland.
  203. 203. Granular cell tumor • These tumors are usually small, although we have seen cases measuring up to 5 cm in diameter. • They have a hard consistency and ill-defined margins • The individual cells are large and their cytoplasm is highly granular . Most granules are small and regular. They alternate with larger round droplets having a homogeneous eosinophilic appearance and a stronger PAS positivity. • The pattern of growth is ill-defined and pseudoinvasive.
  204. 204. Granular cell tumor
  206. 206. Alveolar soft part sarcoma • Site- thigh and leg, oral cavity and pharynx mediastinum ,stomach, retroperitoneum, orbit, bladder, uterus, and vagina. • Most patients are young females. • Grossly, the tumors are well circumscribed, usually large, moderately firm, and gray or yellowish. Areas of necrosis or hemorrhage.
  207. 207. • Microscopically, the tumor cells are separated by fibrous tissue into well-defined nests. Detachment of the central cells results in a typical alveolar pattern . The individual cells are large and have vesicular nuclei, prominent nucleoli, and a granular cytoplasm. Mitoses are exceptional. • PAS stain sometimes demonstrates the presence of diastase-resistant intracytoplasmic needle-like structures .
  208. 208. Alveolar soft part sarcoma The tumor is multinodular, relatively well circumscribed, and embedded within skeletal muscle Typical microscopic appearance of alveolar soft part sarcoma. Note the lack of mitoses
  209. 209. Clear cell sarcoma of tendons and aponeuroses • This malignant tumor arises chiefly from large tendons and aponeuroses of the extremities. • Most of the patients are young adults, and there is a male predominance. • Grossly, the tumors are firm, well circumscribed, and gray or white, and are cut with a gritty sensation . • Microscopically, solid nests and fascicles of pale fusiform or cuboidal cells are present . The nucleoli are large and deeply basophilic. Multinucleated giant cells are often seen. Abundant extracellular and intracellular iron is present. In many of the cases the tumor cells also contain cytoplasmic melanin. • Strongly suggesting that this neoplasm is of neuroectodermal derivation and that it represents a peculiar type of malignant melanoma of soft parts. • Immunoreactivity for S-100 protein, HMB-45, Leu7, NSE, and vimentin.
  210. 210. of clear cell sarcoma (malignant melanoma of soft parts Gross appearance Clear cell sarcoma of soft parts. Note the fascicular pattern of growth and the prominent nucleoli.
  211. 211. Extraskeletal Ewing sarcoma/PNET Tumors morphologically indistinguishable from Ewing sarcoma of the skeletal system can present as soft tissue masses. In some cases, they simply represent soft tissue extensions of tumor originating in the underlying bone. Most of the patients are adolescents or young adults, and the usual sites of involvement are the deep soft tissues of the lower extremity and paravertebral region. Microscopically, like their skeletal counterpart, they are composed of uniform small, round, or oval cells containing cytoplasmic glycogen and sometimes arranged in a ‘peritheliomatous’ pattern .
  212. 212. Extraskeletal Ewing sarcoma/PNET. The tumor is extremely cellular, with hardly any intervening stroma. Some tumor cells are attached to a vessel wall in a pseudorosette arrangement
  213. 213. Phosphaturic mesenchymal tumor • Association between tumors of soft tissue and bone and osteomalacia or rickets. • The syndrome results from tumor production of a renal phosphaturic substance that depletes total-body phosphates by inhibiting tubular reabsorption of phosphate. • It is characterized biochemically by hypophosphatemia, renal phosphate wasting, and decreased serum 1,25-dihydroxyvitamin D3 levels. • The soft tissue tumors associated with this complication have shown an admixture of microscopic features. • Microscopy- characteristic feature has been the association of hemangiopericytoma-like areas and osteoclast-like giant cells, with or without foci of osseous and cartilaginous metaplasia. A ‘grungy’ calcified matrix is said to be particularly distinctive • Immunohistochemically, they usually express fibroblastic growth factor-23 FGF-23.
  214. 214. Phosphaturic mesenchymal tumor A, This area has a hemangiopericytoma-like quality. B, In this area from the same tumor, there is chondroid differentiation and a scattering of osteoclast-like giant cells.
  215. 215. Pleomorphic hyalinizing angiectatic tumor of soft parts (PHAT) • This tumor type can simulate schwannoma by virtue of the angiectatic vasculature, the presence of hemosiderin-laden macrophages, and the occurrence of a spindle cell component with scattered bizarre nuclear forms but practically no mitotic activity . • Two diagnostic clues are represented by the nuclear pseudoinclusions and the fact that many of the bizarre cells are embedded within a fibrinous material surrounding the angiectatic vessels. • CD34 is focally positive and S-100 protein is negative.. • Fig. 25.218 • Cytogenetically, supernumerary ring chromosomes have been found, linking PHAT with other low-grade mesenchymal malignancies, such as dermatofibrosarcoma protuberans, parosteal osteosarcoma, and well- differentiated liposarcoma.[1894] Local recurrences
  216. 216. Pleomorphic hyalinizing angiectatic tumor of soft parts. The pleomorphic tumor cells surround dilated vessels.
  217. 217. Chondrosarcoma
  218. 218. Soft tissue Osteosarcoma
  219. 219. PNET (Ewings tumor)