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osteogenic bone tumors & fibrous dysplasia

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osteogenic bone tumors & fibrous dysplasia

  1. 1. BONE FORMING TUMOURS & FIBROUS DYSPLASIA Presented by: ARUN KUMAR Moderator: Dr. SHIKHA PRAKASH
  2. 2. NORMAL BONE Parts of bones 1. Epiphysis : ends of bone 2. Diaphysis : shaft 3. Metaphysis : epiphysial end of diaphysis Macroscopically the architecture of bone may be 1. Compact 2. cancellous/spongy/trabeculae
  3. 3. NORMAL BONE On longitudinal section the bone is composed of : 1. Periosteum 2. Cortex 3. endosteum 4. Medullary cavity
  4. 4.  Unmineralised matrix laid down by osteoblasts  Stains homogenously pink on H&E  On polarized light demonstrates criss cross or woven pattern of collagen fibers  Can be confused with fibrin, collagen or chondroid. OSTEOID
  5. 5. NORMAL BONE Woven bone : In these, collagen is deposited in a random weave manner. Lamellar bone : Collagen is deposited in a order. It replaces woven bone during growth ,deposited much slowly & stronger than woven bone
  6. 6. Woven bone (top) deposited on the surface of preexisting lamellar bone(bottom)
  7. 7. WHO CLASSIFICATION OF BONE TUMOURS
  8. 8. Histologic Type Benign Malignant Chondrogenic (22%) Osteochondroma Chondrosarcoma Chondroma Dedifferentiated chondrosarcoma Chondroblastoma Mesenchymal chondrosarcoma Chondromyxoid fibroma clear cell chondrosarcoma Osteogenic (19%) Osteoid osteoma Osteosarcoma Osteoblastoma Fibrogenic Desmoplastic fibroma
  9. 9. notochordal tumors Chordoma Histiocytic origin Benign Fibrous histiocytoma Malignant fibrous histiocytoma Ewing’s sarcoma/PNET Giant cell tumor Malignant Giant cell tumor Hematopoietic (40%) Myeloma Malignant lymphoma Joint lesions Synovial chondromatosis Vascular Hemangioma Hemangioendotheliom a Hemangiopericytoma, angiosarcoma
  10. 10. Lipogenic Lipoma Liposarcoma Neurogenic Neurilemmoma Smooth muscle tumors Leiomyoma Leiomyosarcoma Miscellaneous tumors Adamantinoma Metastatic malignancy Tumours of unidentified neoplastic nature Aneurysmal bone cyst Simple cyst Fibrous dysplasia Langerhan’s cell histiocytosis Chest wall hamartoma Osteofibrous dysplasia
  11. 11. BONE FORMING TUMOURS 1. OSTEOID OSTEOMA 2. OSTEOBLASTOMA 3. OSTEOSARCOMA  CONVENTIONAL OS  TELANGIECTATIC OS  SMALL CELL OS  LOW GRADE CENTRAL OS  SECONDARY OS  PAROSTEAL OS  PERIOSTEAL OS  HIGH GRADE SURFACE OS
  12. 12. OSTEOID OSTEOMA
  13. 13. OSTEOID OSTEOMA  Benign lesion characterized by less than 2 cm pea like mass of abnormal bone-nidus  Limited growth potential  Clinical features 1. children & adolescents, occasionally in older individuals 2. more common in males 3. any bone except sternum. 1. most common in the long bones (metaphysis or shaft). 2. The tumour tend to involve the cortex rather than medulla
  14. 14. OSTEOID OSTEOMA  Signs & symptoms: 1. Pain-characteristically relieved by salicylates and NSAIDS 2. Swelling & redness 3. Joint effusion 4. Scoliosis 5. Bone growth abnormalities  Genetics : involvement of 22q13 & loss of 17q
  15. 15. OSTEOID OSTEOMA: RADIOLOGIC FINDINGS  X-RAY : Dense cortical sclerosis surrounding a radiolucent nidus,  CT SCAN : best imaging study to demonstrate OO, help
  16. 16. OSTEOID OSTEOMA: RADIOLOGIC FINDINGS  MRI SCAN: Useful in demonstrating medullary or periarticular lesions and peri-tumoural oedema, also help to localize the lesion BONE SCAN: associated with hot bone scan, helpful in localizing the lesion
  17. 17. OSTEOID OSTEOMA : GROSS FINDINGS Small , cortically based, red, gritty or granular round lesion surrounded (well circumscribed) by ivory white sclerotic bone
  18. 18. MICROSCOPIC FINDINGS  The tumour consists of a central area of vascularised connective tissue within which differentiating osteoblasts are engaged in the production of osteoid and sometime bone  if actual bone is present osteoclast may also be seen engaged in remodelling
  19. 19. OSTEOID OSTEOMA Low power view showing wedge shaped nidus protruding slightly above the surface and surrounded by sclerotic bone Central nidus with dense sclerotic bone
  20. 20. Osteoid osteoma shows anastomosing irregular bony trabeculae with osteoblastic rimming embedded in a hypocellular fibrovascular stroma
  21. 21. PROGNOSIS  Prognosis is excellent  Recurrence is rare
  22. 22. DIFFERENTIAL DIAGNOSIS  SOLITARY ENOSTOSIS  OSTEOMYELITIS  BRODIE’S ABSCESS  OSTEOBLASTOMA  OSTEOSARCOMA
  23. 23. Osteoid osteoma v/s Solitary enostosis SOLITARY ENOSTOSIS : does not cause pain or host bone sclerosis. Usually consists of lamellar bone with haversian systems
  24. 24. Osteoid osteoma v/s Osteomyelitis Chr osteomyelitis : showing necrotic bone,chr inflammation & fibrosis
  25. 25. Osteoid osteoma v/s Brodie’s abscess Image shows fibrosis , degenerating bony spicules, & subacute inflammation
  26. 26. OSTEOBLASTOMA
  27. 27. OSTEOBLASTOMA  A rare benign tumor, usually larger than 2 cm, characterized by osteoid and woven bone production.  Age: 10-30 yrs  M:F is 2.5:1  Skeletal distribution: predilection for spine particularly posterior elements and sacrum, others- long bones-proximal and distal femur, proximal tibia  Site: majority intra-osseus but a small percentage can occur on the surface of the bone in a
  28. 28. OSTEOBLASTOMA Symptoms: dull, aching, nocturnal pain not relieved by aspirin Genetics : 1. chromosomal rearrangements have been described in 4 cases, with chr no. ranging from hypodiploid to hyperdiploid. 2. MDM2 amplification 3. TP53 deletion in aggressive osteoblastoma
  29. 29. OSTEOBLASTOMA: RADILOGICAL FINDINGS  SPINAL LESION 1. Main mass centered in vertebral arch 2. Round to ovoid lytic lesion with bone expansion 3. Periosteal new bone formation 4. Intra-lesional bone forming
  30. 30. X-ray showing expansion of the left fourth lumbar pedicle : transeverse process and superior facet
  31. 31. OSTEOBLASTOMA: GROSS FINDINGS  Lesion is well demarcated,  Round to oval with thin cortex  Mostly granular, gritty, & deep red on cutting  Whitish yellow if bone
  32. 32. Osteoblastoma: excised specimen of femoral lesion showing a well demarcated fleshy tumour
  33. 33. OSTEOBLASTOMA: MICROSCOPIC FINDINGS  Tumour is composed of woven bone spicules or trabeculae which are arranged haphazardly & lined by single layer of osteoblast  Rich vascularity  Osteoblast may have mitosis but not atypical  Scattered multinucleated giant cells often present
  34. 34. OSTEOBLASTOMA: MICROSCOPIC FINDINGS  Tumour has a pushing border  Secondary ABC like changes may be seen  Some osteoblastomas show multiple small nidi
  35. 35. Osteoblastoma shows trabeculae of woven bone lined by layer of polygonal osteoblast and the well vascularised inter-trabecular stroma
  36. 36. OSTEOBLASTOMA: MICROSCOPIC FINDINGS Malignant osteoblastoma : histologically same but are more cellular, has large no. of giant cells & large amount of spiculated blue bone. locally aggressive & does not develop distant metastasis Aggressive osteoblastoma : characterised by presence of epitheloid osteoblasts, trabecular or sheet-like osteoid & osteosclerotic resorption. locally aggressive & does not develop distant metastasis Pseudomalignant osetoblastoma : tumor cells have hyperchromatic nuclei. However, the nuclei have the
  37. 37. Osteoblastoma : prominent epithiloid appearance
  38. 38. OSTEOBLASTOMA : PROGNOSIS Prognosis is excellent Recurrence is unusual and may occur in a bone which has difficult surgical access
  39. 39. OSTEOBLASTOMA:D/D 1.Osteoid osteoma 2.Osteosarcoma 3.Giant cell tumor 4.Aneurysmal bone cyst
  40. 40. 0steoid osteoma osteoblastoma 1. involvement Every bone except sternum Predilection for spine 2. size < 2cm > 2cm 3. pain Characteristically relieved by NSAIDs Not relieved by NSAIDs 3. imaging Dense, cortical sclerosis surrounding a radiolucent nidus Lytic, well circumscribed , confined by a periosteal shell of reactive bone 4. gross Gritty or granular round lesion surrounded by ivory white sclerotic bone Round to oval, thinned cortex & periosteal reactive bone 5. microscopy Central nidus with dense sclerotic bone Composed of woven bone trabeculae arranged haphazardly
  41. 41. Osteoblastoma v/s GCT GIANT CELL TUMOR: located in epiphysis, packed with giant cells and stromal cells
  42. 42. OSTEOBLASTOMA: D/D ABC Osteoblastoma 1. Age First 2 decade 10-30yr 2. Sex No sex predilection M>F 3. Site Metaphysial Majority intraosseus 4. Gross Well demarcated, multiloculated mass of blood filled cystic spaces separated by tan white gritty septa Well demarcated, round to oval. Granular, gritty & deep red on cutting 5. Microscopy 6. Recurrence Well circumscribed, blood filled cystic spaces, separated by fibrous septa rich in collagen producing fibroblasts & callus like tissue Tumor composed of haphazardly arranged woven bone spicules or trabeculae Unusual
  43. 43. Osteoblastoma v/s ABC ABC with blood filled cystic space surrounded by wall containing proliferating fibroblasts, reactive woven bone, & osteoclast type giant cells
  44. 44. OSTEOSARCOMA
  45. 45. OSTEOSARCOMAS  Osteosarcomas is a mesenchymally derived malignant tumor that produces osteoid and/or bone.  They can be: 1. INTRAMEDULLARY OS 2. INTRACORTICAL OS 3. JUXTACORTICAL OS
  46. 46. OSTEOSARCOMA  PRIMARY OSTEOSARCOMA 1. CONVENTIONAL OSTEOSARCOMA a) Osteobalstic b) Chondroblastic c) Fibroblastic 2. SMALL CELL OSTEOSARCOMA 3. TELANGIECTATIC OSTEOSARCOMA 4. LOW GRADE CENTRAL OSTEOSARCOMA
  47. 47. OSTEOSARCOMA 5. SURFACE OSTEOSARCOMA a) Parosteal osteosarcoma b) Periosteal osteosarcoma c) High grade surface osteosarcoma  SECONDARY OSTEOSARCOMA 1. Osteosarcoma in paget’s disease 2. Postirradiation osteosarcoma 3. Osteosarcoma in other benign precursors
  48. 48. age/sex site c/f prognosis Convention al OS 2nd decade M>F Metaphysis (91%) of long bones Pain,swellin g,path # If untreated fatal Telangiectat ic OS (<4%) 2nd decade M>F Metaphysis of long bones Pain,swellin g ,path # As above Small cell OS(1.5%) 2nd decade, slightly mc in female >50% metaphysis of long bones Pain,swellin g Slightly worse than convention al OS Low grade central OS(1-2%) 2nd-3rd , M=F 80% in long bones Pain,swellin g excellent
  49. 49. age/sex site c/f prognosis OS sec. to paget ds 65yr M>F,2:1 Long bones, pelvis, skull Pain, swelling, path# Poor Post- radiation OS (3.4%- 5%) Children are at greatest risk Any bone, mc in pelvis & shoulder region Pain, swelling 5yr survival rate for extremity lesion is 68.2% & axial lesion 27.3% Parosteal OS Young adult, slight female predominan ce Long bones Pain, swelling, inability to flex the knee excellent
  50. 50. age/sex site c/f prognosis Periosteal OS 2nd-3rd decade Slightly mc in male Diaphysial or dia-meta region of long bones Painless swelling initially, later pain excellent High grade surface OS 2nd decade, slightly mc in male Long bones Mass &/or pain Depend upon response to chemothera py
  51. 51. CONVENTIONAL OSTEOSARCOMA
  52. 52. CONVENTIONAL OS:RADIOLOGIC FINDINGS  Metaphysial location  It may be pure oseoblastic or osteolytic. In most cases it is mixed lytic/blastic lesion accompanied by cortical destruction and extension into soft tissue  Tumours tend to be eccentric. Mixed blastic/lytic lesion involving the femoral metaphys
  53. 53. CONVENTIONAL OS:RADIOLOGIC FINDINGS  Periosteal reaction: 1. Codman’s triangle 2. Longitudinal laminations 3. Perpendicular spiculations  Soft tissue mass
  54. 54. CONVENTIONAL OS :GROSS FINDINGS  OS often a large (over 5cm), metaphysial centered , fleshy or hard tumour which may contain cartilage  It frequently transgresses the cortex & is associated with a soft tissue mass
  55. 55. CONVENTIONAL OS :MICROSCOPIC FINDINGS 1. It is highly anaplastic , pleomorphic tumor. 2. The tumour cells may be epithelioid ,plasmacytoid , fusiform, ovoid, small round cells, clear cells, giant cells or spindle cells. Most cases are mixture of 2 or more of these cell types. 3. Osteoid and/or bone production by tumor cells. dense, pink, amorphous,curvilinear with small nubs,arborisation,abortive lacunae formation, intercellular material.
  56. 56. On the basis of production of predominant matrix by tumors the conventional OS is subdivided into: 1. OSTEOBLASTIC (50%) 2. CHONDROBLASTIC (25%) 3. FIBROGENIC (25%)
  57. 57. OSTEOBLASTIC OSTEOSARCOMA 1. Bone &/or osteoid are the predominant matrix 2. The matrix may be thin, arborising osteoid (i.e., filigree) to dense compact osteoid & Osteoblastic OS: showing osteoid
  58. 58. OSTEOBLASTIC OSTEOSARCOMA Filigree osteoid comprises thin, randomly arborizing lines of osteoid interweaving b/w neoplastic cells Flat and thick osteoid
  59. 59. CHONDROBLASTIC OSTEOSARCOMA  Chondroid matrix is predominant.  It tends to be high grade hyaline cartilage.  Myxoid and other forms of cartilage are uncommon, except in the jaws & pelvis.  Osteoid is seen between spindle cells or in center of chondroid lobules.
  60. 60. CHONDROBLASTIC OSTEOSARCOMA Lobules of malignant cartilage. There is spindling at the periphery and osteoid formation.
  61. 61. FIBROBLASTIC OSTEOSARCOMA  25% of all conventional osteosarcoma  A high grade spindle cell malignancy  Minimal matrix production
  62. 62. Unusual forms of osteosarcoma 1.Epitheloid osteosarcoma 2.Ostoblastic osteosarcoma – sclerosing type 3.Osteosarcoma resembling osteoblastoma 4.Chondromyxoid fibroma-like osteosarcoma 5.Chondroblastoma-like osteosarcoma 6.Clear cell osteosarcoma 7.Malignant fibrous histiocytoma-like osteosarcoma 8.Giant cell rich osteosarcoma Not associated with specific biologic behaviour that differs from conventional osteosarcoma.
  63. 63. TELANGIECTATIC OSTEOSARCOMA
  64. 64. TELANGIECTATIC OSTEOSARCOMA Lytic lesion , poorly marginated, Cortical bone destruction without distinct surrounding bony sclerosis Periosteal reaction frequent
  65. 65. TELANGIECTATIC OSTEOSARCOMA Tumor has hemorrhagic red-brown appearance resembling blood clot
  66. 66. TELANGIECTATIC OSTEOSARCOMA Resmbles aneurysmal bone cyst at low power TELANGIECTATIC OSTEOSARCOMA Shows malignant osteoid
  67. 67. TELANGIECTATIC OSTEOSARCOMA Hypercellular pleomorphic stromal cells within solid septa adjacent to cystic space. Mitosis seen
  68. 68. SMALL CELL OSTEOSARCOMA
  69. 69. Small cell OS of distal femur : X-ray image showing lytic and blastic tumour tissue at the soft tissue compartment of the lesion. SMALL CELL OSTEOSARCOMA
  70. 70. SMALL CELL OSTEOSARCOMA GROSS : Indistinguishable from those of conventional OS HISTOPATHOLOGY •Small cells associated with osteoid production. •Tumours are classified according to predominant cell type : round cell type or spindle cell type. •The nuclear diameter of round cells can be very small(comparable to Ewing sarcoma) to large(comparable to large cell lymphoma).
  71. 71. Small cell osteosarcoma, small cell type. Osteoid production at lower right.
  72. 72. CENTRAL LOW GRADE OSTEOSARCOMA
  73. 73. CENTRAL LOW GRADE OSTEOSARCOM A Cut surface shows a grey white tumour with a firm & gritty texture arising from the medullary cavity.
  74. 74. CENTRAL LOW GRADE OSTEOSARCOMA Microscopy  Tumor is composed of hypocellular spindle cell proliferation.  The osteogenic matrix is produced as well formed trabeculae of bone.  The spindle cell show minimal cytolgical atypia  Mitotic figures are sparse.  The tumor tend to permeate marrow fat & surrounding bony trabeculae.
  75. 75. CENTAL LOW GRADE OSTEOSARCOMA Bony trabeculae surrounded by a hypocellular spindle cell stroma with minimal cytologic atypia.
  76. 76. OS SECONDARY TO PAGET'S DISEASE
  77. 77. OS SECONDARY TO PAGET'S DISEASE Grossly : destructive tumors along with fleshy soft tumors  Microscopically: high grade OS, mostly osteoblastic or fibroblastic. A great number of osteclast like giant cell may be found. Genetics : linked to 18q
  78. 78. PAGET’S SARCOMA Proximal femur shows thickened cortical and medullary bone characteristic of underlying paget’s disease with a large hemorrhagic tan-white sarcomatous tumor that has broken through cortex
  79. 79. PAGET’S SARCOMA High grade osteosarcoma permeating abnormal bone seen in Paget’s disease which is thickened and lined by osteoclasts
  80. 80. POST-IRRADIATION SARCOMA
  81. 81. POSTIRRADIATION SARCOMA Criteria for diagnosis 1. The affected bone may have been normal/benign tumour/non-bone forming malignancy. 2. History of prior radiation therapy & tumour developed in the path of radiation beam. 3. A symptom free latent period must follow. 4. Sarcoma must be biopsy proven.
  82. 82. DIFFERENTIAL DIAGNOSIS OF OS  CALLUS  OSTEOBLASTOMA  ANEURYSMAL BONE CYST  CHONDROBLASTOMA  GCT  EWING’S SARCOMA  MALIGNANT LYMPHOMA  CHONDROSARCOMA  FIBROSARCOMA  FIBROUS DYSPLASIA
  83. 83. HISTOLOGIC FEATURES CALLUS OSTEOBLASTOM A OSTEOSARCOM A Osteoblastic rimming +++ 0-++ 0 Trapping of host lamellar bone 0-++ 0 ++-+++ Circumscribed 0 +++ 0 Lesional fibrous tissue 0-+++ No ++-+++ Lesional hyaline cartilage 0-+++ Very rare 0-++++ Scattered atypical nuclei 0 Rare 0-++++ Atypical mitotic figures 0 0 0-++++ Extensive necrosis 0-+ 0 0-+++
  84. 84. Osteosarcoma v/s callus
  85. 85. HISTOLOGIC FEATURES ANEURYSMAL BONE CYST TELANGIECTATIC OSEOSARCOMA Osteoblastic rimming 0-++ 0 Trapping host lamellar bone - 0-++++ Pure woven bone Yes or no Yes Lesional fibrous tissue 0-+ 0-++ Scattered atypical nuclei Rare +-+++ Atypical mitotic figures 0 0-+++ Large blood filled cysts +-++++ +++ Extensive necrosis 0-+ +-++++ Anaplasia - Yes
  86. 86. Osteosarcoma v/s ABC ABC with blood filled cystic space surrounded by wall containing proliferating fibroblasts, reactive woven bone, & osteoclast type giant cells
  87. 87. HISTOLOGIC FEATURES FIBROUS DYSPLASIA LOW GRADE OS Osteoblastic rimming 0 0-+ Trapping host lamellar bone 0 0-++ Pure woven bone Yes Usually no C &Y spicules of bone Yes No Lesional fibrous tissue ++-+++ +-++ Lesional hyaline cartilage Rare 0-++ Scattered atypical nuclei Rare +-++ Atypical mitosis 0 0-+ Extensive necrosis 0 0-+
  88. 88. DIFFERENTIAL DIAGNOSIS OF OS Chondroblastoma : Epiphyseal centering , it is rarely occur in OS Fibrosarcoma : Not associated with any tumor osteoid, bone, or cartilage Chondrosarcoma : >50yr, cartilage forming tumor, on X- ray it present as area of radiolucency with variably distributed punctate opacities, periosteal reaction is absent or minimal, osteoid is absent
  89. 89. Osteosarcoma v/s GCT Giant cell tumor : epiphysial centering, occur in 20-40yr, show bone expanding & eccenteric area of lysis, & multinucleated giant cells on
  90. 90. Features distinguishing both are: 1. Location 2. Codman’s triangle 3. Intralesional bone fluffs 4. Anaplasia of stromal cells 5. Production of malignant osteoid OSTEOSARCOMA vs GCT
  91. 91. OS v/s Ewing sarcoma Ewing sarcoma : More common in men, pelvis & ribs are mc site, onion skin periosteal reaction seen on X-ray & on histo composed of small round cells with
  92. 92. Osteosarcoma v/s Chondroblastoma Image showing eosinophilic chondroid matrix with calcific deposit.The mononuclear cells contain round to oval nuclei sorrounded by pink cytoplasm. Hyaline cartilage & atypical mitosis
  93. 93. Osteosarcoma v/s Chondrosarcoma Chondrosarcoma permeates around pre-existing trabecular bone
  94. 94. OSTEOSARCOMAS OF SURFACE BONES  PAROSTEAL OSTEOSARCOMA  PERIOSTEAL OSTEOSARCOMA  HIGH GRADE SURFACE OSTEOSARCOMA
  95. 95. PAROSTEAL OSTEOSARCOMA
  96. 96. PAROSTEAL OSTEOSARCOMA Radiologic findings: heavily mineralised mass attached to cortex, with broad base
  97. 97. PAROSTEAL OSTEOSARCOMA  Gross findings: 1. Hard lobulated mass attached to cortex 2. Nodules of cartilage may be present; occ cartilage may be incomplete cap like 3. Soft at periphery 4. Fleshy, soft areas
  98. 98. PAROSTEAL OSTEOSARCOMA  Microscopic findings: 1. Well formed bony trabeculae 2. Hypocellular stroma 3. With or without osteoblastic rimming 4. Stromal cells show minimal atypia 5. 20% show moderate atypia 6. 50% of the tumour show cartilage differentiation
  99. 99. Moderately atypical spindle tumor cells grow between irregularly shaped bone trabeculae Shows mature appearing bone surrounded by a hypocellular fibroblastic stroma with minimal cytologic atypia
  100. 100. DIFFERENTIAL DIAGNOSIS  Fibrous dysplasia  Myositis ossificans : It does not involve cortex, show much more cellularity than parosteal OS & atypical mitosis not seen  Osteochondroma : In osteochondroma radiography shows continuity between the bone and the osteochondroma, and the intertrabecular spaces contain fatty or hematopoietic marrow
  101. 101. Parosteal OS v/s Myositis Ossificans MO showing osteoid production in a cellular fibrous tissue
  102. 102. Parosteal OS V/S Osteochondroma Image showing thickened hyaline cartilage cap which mature via enchondral calcification to bony trabeculae surrounded by fat & hematopoietic marrow
  103. 103. PERIOSTEAL OSTEOSARCOMA
  104. 104. PERIOSTEAL OSTEOSARCOMA  Radiologic findings: 1. Sunburst appearance 2. Codman’s triangle is frequent 3. Cortex appears thickened 4. CT-scan & MRI : important in the evaluation of tumor size, integrity of cortex, soft tissue extension, & relationship to soft tissue bundle
  105. 105. PERIOSTEAL OSTEOSARCOMA  Gross findings: 1. Tumor arises from bone surface 2. May involve part or entire circumference 3. Calcified spicules can be seen, longest in center and tapering on both sides 4. Well delineated by capsule/pseudocapsule 5. Merges imperceptibly with cortex at base
  106. 106. PERIOSTEAL OSTEOSARCOMA  Microscopic findings: 1. Tumour is arranged in lobules with moderately atypical chondrocytes 2. There is spindling at the periphery & spindle cells shows matrix production 3. The centre of the chondroid lobule also show bone formation
  107. 107. PERIOSTEAL OSTEOSARCOMA Shows malignant chondroid matrix merging with osteoid
  108. 108. HIGH GRADE SURFACE OSTEOSARCOMA
  109. 109. HIGH GRADE SURFACE OSTEOSARCOMA Radiologic findings: surface lesion , partially mineralized, mass extending in soft tissue Underlying cortex is destroyed with periosteal new bone formation
  110. 110. HIGH GRADE SURFACE OSTEOSARCOMA  Gross findings: 1. Situated on surface of bone 2. Underlying cortex is eroded 3. Surface is multilobulated 4. Colour depends on amount of chondroid matrix, hemorrhage & necrosis 5. Soft areas separate it from parosteal osteosarcoma
  111. 111. HIGH GRADE SURFACE OSTEOSARCOMA  Microscopic findings: same features seen in conventional OS 1. Show osteoblastic, fibroblastic or chondroblastic differentiation 2. High grade cytologic atypia 3. Lace like osteoid 4. Chondroblastic area rich tumor may be confused with periosteal osteosarcoma
  112. 112. HIGH GRADE SURFACE OS: DIFFERENTIAL DIAGNOSIS 1. Parosteal OS :pattern of osteoid production & high grade cytological atypia is seen in high grade OS 2. Periosteal OS : In high grade OS, tumour shows larger regions of spindle cell morphology & more cellular atypia
  113. 113. Fibrous dysplasia
  114. 114. Fibrous dysplasia • Benign medullary fibro-osseous lesion • May involve one or more bone • Occur in children & adults with equal sex distribution • Sites : m.c. in jaw bones,in women long bones & in men ribs & skull are favoured sites • Types : 1. monostotic form(more common) : skull more commonly followed by femur, tibia, ribs 2. polystotic form : femur, pelvis, tibia in majority of cases
  115. 115. Fibrous dysplasia : Radiographic features -Often show a non- aggressive lesion with a ground glass matrix -No soft tissue extension -periosteal reaction is not seen unless there is a complicating fracture -CT-scan & MRI better define the extent There is a well defined lucency with Sclerotic margins
  116. 116. Fibrous dysplasia : Gross features The bone is often expanded  tan grey colour firm-to-gritty consistency. There my be cysts, which may contain some yellow- tinged fluid circumscribed blue tinged translucent material if cartilage is
  117. 117. Fibrous dysplasia : Microscopy  Well cirumscribed  Composed of fibrous & osseus component The fibrous component is composed of bland spindle cell with low mitotic rate The osseus component is comprised of irregular curvilinear trabeculae of woven bone(rarely lamellar bone) Secondary changes : foam cells, multinucleated giant cells, aneurysmal bone cyst or myxoid changes
  118. 118. Fibrous dysplasia : Microscopy The fibrous stroma is composed of bland spindle cells arranged in whorled or storiform pattern
  119. 119. Fibrous dysplasia : Microscopy Anastomoting trabeculae of immature woven bone without osteoblastic rimming
  120. 120. Fibrous dysplasia : Microscopy Curvilinear trabeculae often describing as resembling ‘Chinese characters’
  121. 121. Fibrous dysplasia : Microscopy Characteristic C shaped bony spicules with spindle cell stroma
  122. 122. Fibrous dysplasia : D/D 1. Parosteal OS : • juxtacortical position, • show moderate stromal anaplasia 2. Low grade intramedullary OS; fibrous dysplasia like : •radiologically more aggresive, & • lack rim of benign host bone sclerosis
  123. 123. Fibrous dysplasia : D/D 3. Osteofibrous dysplasia : exclusively seen in tibia &/or fibula of children < 10yr, show predilection for cortex, characteristically shows focal to diffuse osteoblastic rimming of the bone trabeculae
  124. 124. Fibrous dysplasia Genetics :1. Mutation in GNAS1 in monostotic & polystotic forms 2. structural rearrangements involving 12p13 & trisomy 2 Prognosis : good , rarely malignant transformation may occu
  125. 125. SUMMARY Constant fundament al tissue Variable fundament al tissue Reactive tissue (possible) Benign to locally aggressive tumor Malignant tumor Osteoid, &/woven bone A. Cartilage B. No cartilage Fibrous, OLGCs, osteoclasts osteoclasts Callus(early to mid),periost itis ossificans OO,OB Osteosarco ma all types Osteoid , woven bone, & cartilage Osteoclasts like giant cells Fibrous dysplasia Parosteal OS
  126. 126. THANK YOU

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