1. Soft tissue tumors can arise from adipose, fibrous, skeletal muscle, smooth muscle, vascular, and peripheral nerve tissues. They range from benign to malignant. 2. Malignant soft tissue tumors are graded I-III based on differentiation, with grades I-II having potential for recurrence but low risk of metastasis. Prognosis depends on histologic type, grade, size, and anatomic site. 3. Examples of benign and malignant soft tissue tumors mentioned include lipomas and liposarcomas of adipose tissue, nodular fasciitis and fibrosarcomas of fibrous tissue, and rhabdomyomas and rhabdomyosarcomas of skeletal

1. dr. Sanggam B Hutagalung, M.BioMed,SpPA
Dept. Patologi Anatomi Fakultas Kedokteran
Universitas Methodist Indonesia
PATOLOGI SISTEM
MUSCULOSKELETAL
Joint and Soft tissue diseases

2. SOFT TISSUE TUMORS.
• Adipose tissue.: Lipomas –Liposarcomas
• Fibrous tissue: Fibroma-Fibrosarcoma
• Skeletal muscle : Rhabdomyoma ,
Rhabdomyosarcoma
• Smooth muscle: Leiomyoma-Leiomyosarcoma
• Vascular tumors: Hemangioma-Angiosarcoma
• Peripheral nerve tumors.
• Unknown exact cell of origin

3. • Malignant soft tissue tumors are graded
according to differentiation into I-III grades
• Grades I&II may recur but rarely metastasize
prognosis of malignant tumours depends on the
histologic type,its degree of differentiation (
Grade), size and the anatomic site( Stage).
• The prognosis depends on Type, Grade,
Stage, & Site

4. Tumors of Adipose tissue:
Lipoma
• Commonest of soft tissue tumors
• Most in subcutaneous tissue
• Single or multiple, may be familial
• No malignant transformation
• Grossly : Circumscribed yellow mass
• Histologically : Mature fatty tissue
• Many histological variants

5. Liposarcoma
• Adults 50-60yrs
• Deep soft tissue & retroperitoneum
• Grossly : Large yellow glistening mass
• Histologically :
– Low grade : Well differentiated & Myxoid
– High grade :Round & Pleomorphic
(Diagnosis depends on identification of lipoblasts)
• Prognosis depends on type

6. FAT
• LIPOMA
• LIPOSARCOMA
NORMAL FAT LIPOMA,
encapsulated
LIPOSARCOMA, often
retroperitoneal

8. • Fibrous Tumors & Reactive
Proliferations

9. 1- Nodular fasciitis
Reactive fibroblastic proliferation frequently
misdiagnosed as sarcoma.
Mostly affects young adults and presents as
rapidly enlarging sometimes painful mass .
Location:- Upper extremity and trunk.
10% of patients have history of local trauma.
Self limiting
Similar reactive lesion is Myositis Ossificans

10. Morphology
Grossly: Unencapsulated < 3 cm mass in
subcutaneous tissue, muscle or fascia
Micro:- immature appearing fibroblasts with
high mitoses but no atypia set in myxoid
background.
( Tissue culture like appearance)

12. 2- Fibromatosis
 A group of fibroblastic proliferation, grow in
infiltrative fashion and to recur after surgical excision
but do not metastasize.
 Various age groups ,various gene mutations
 Two types:
A. Superficial:- palmar (Dupuytren contracture) and
penile ( Peyronie disease)
B. Deep called desmoid tumours that arise in the
abdomen,muscles of the trunk and extremities and
these tend to be more aggressive.

13. 3-Fibrosarcoma
Mostly affects adults, rare congenital in infants
Sites:- Deep tissues of thighs,knees and
retroperitoneum.
They tend to grow slowly.
Gross: are solitary,infiltrative or well circumscribed.
Micro: Fasicles of fibroblasts arranged in herringbone
appearance
Recurrence and metastatic rates depend on the grade.

15. 4- Fibrohistiocytic Tumors
• Several types
• Benign & malignant
• Most are in adults
• Superficial usually benign
• Deep often malignant, larger, highly
pleomorphic, metastasizing.
• Treatment by excision

16. Benign Fibrous Histiocytoma :
(Dermatofibroma)
• Common tumor
• Circumscribed tumor in dermis or
subcutaneous tissue < 1 cm.
• Histology : Spindle cells & histiocytes
No mitoses
Dermatofibrosarcoma Protruberance :
• As above, but larger, deeper
• Mitoses present, CD 34 positive
• Recurs after excision

17. • Tumors of Smooth Muscle :
• Benign : Leiomyoma , mainly uterine
but could arise from vascular smooth muscle
anywhere
• Malignant : Leiomyosarcoma,uterus or
soft tissue.
Superficial or large retroperitoneum or
extremities.

18. • Tumors of Skeletal Muscle

19. Rhabdomyosarcoma :
• Commonest sarcoma of children,adolescents
& young adults.
• Chromosomal translocation t(2;13)produces a
fusion gene (PAX gene) controlling muscle
differentiation
• Sites: Soft tissue, head & neck, genito-urinary
tract
• Aggressive tumor, treated by surgery,chemo
& radiation

20. SKELETAL MUSCLE
• RHABDOMYOMA
• RHABDOMYOSARCOMA

21. • Types :
 Embryonal:- most common type mainly
in head & neck, genitourinary &
retroperitoneum.
 Alveolar type: in extremities of
adolescents.
 Pleomorphic: in soft tissues of adults.
Diagnostic cell is the Rhabdomyoblast
which is Tadpole or Strap cell

22. Diseases of skeletal muscle

23. Diseases of skeletal muscle.
 Muscular atrophy
 Neurogenic atrophy
Muscular Dystrophies
 Duchenne muscle dystrophy.
 Becker muscle dystrophy.
Neuromuscular junction disorders.
 Myasthenia Gravis.
Inflammatory myopathies.
Inherited metabolic & congenital diseases.
Acquired metabolic and toxic diseases.

24. Spinal muscular atrophy with groups of atrophic muscle fibers resulting
from denervation atrophy of muscle in early childhood.
Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 28 September 2009 11:10 PM)
© 2007 Elsevier

25. A, Dermatomyositis. Note the rash affecting the eyelids.
B, Dermatomyositis. The histologic appearance of muscle shows
perifascicular atrophy of muscle fibers and inflammation..
Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 28 September 2009 11:10 PM)
© 2007 Elsevier

27. FIBROUS TISSUE
• NODULAR FASCIITIS (pseudosarcomatous)
• FIBROMATOSES (plantar,
palmar, penile)
• FIBROSARCOMA

28. FIBROHISTIOCYTIC
• FIBROUS HISTIOCYTOMA
• DERMATOFIBROSARCOMA PROTUBERANS
• MALIGNANT FIBROUS HISTIOCYTOMA

29. SMOOTH MUSCLE
• LEIOMYOMA
• LEIOMYOSARCOMA

32. VASCULAR
• HEMANGIOMA
• LYMPHANGIOMA
• HEMANGIOENDOTHELIOMA
• HEMANGIOPERICYTOMA
• ANGIOSARCOMA

33. PERIPHERAL NERVE
• NEUROFIBROMA
• SCHWANNOMA
• GRANULAR CELL TUMOR
• MALIGNANT (SCHWANNOMA)

34. UNCERTAIN
• SYNOVIAL SARCOMA
• ALVEOLAR “SOFT PART” SARCOMA
• EPITHELIOD SARCOMA