Soft Tissue Tumors

1. Soft Tissue Tumors Lucy H. Liu, M.D. Department of Pathology University of Illinois at Chicago e-mail: lucyliu@uic.edu

2. Soft Tissue Tumors UIC College of Medicine M2 Pathology Course, Lecture # 63 Tuesday, January 28, 2003 11:30 am

3. Soft Tissue Tumors Lecture Goals: 1. Nomenclature & classification system of tumors 2. Differences between benign and malignant tumors 3. Clinical & morphologic features of common tumors 4. Approach to diagnosis of soft tissue tumors

4. Soft Tissue Tumor • Neoplastic conditions arising in • extraskeletal mesodermal tissues -- Fibrous tissue -- Smooth muscle -- Skeletal muscle -- Adipose tissue -- Blood & lymphatic vessels -- Peripheral nerves - neuroectoderm

5. Soft Tissue Tumor General principles for diagnosis: • Location -- Deep lesions tend to be malignant -- Superficial lesions - benign • Size -- Larger tumors tend to be malignant • Growth pattern -- Rapidly growing - malignant -- Infiltrating - malignant • Metastasis -- Malignant

6. Soft Tissue Tumors Approach to Diagnosis • Histological morphology • Immunohistochemistry • Cytogenetic study • Molecular analysis • Ultrastructure

7. Soft Tissue Tumors Immunohistochemistry • Cytokeratin • Vimentin • Smooth muscle actin • Desmin • S-100 • CD 31 • CD 34

8. Soft Tissue Tumors Cytogenetic Changes • t( 2:13) Alveolar rhabdomyosarcoma • t( 11;22) Ewing’s sarcoma/PNET • t( 11;22) Desmoplastic small round cell tumor • t( 12;16) Myxoid liposarcoma • t( 9;22) Myxoid chondrosarcoma • t(12;22) Clear cell sarcoma • t( X;18) Synovial sarcoma

9. Nodular Fasciitis • Benign reactive soft tissue lesion • Probably secondary to trauma • On forearm, trunk, back- well circumscribed • Spindle cells ( fibroblasts & myofibroblasts) in loose matrix -“fibroblasts in tissue culture” • Rapid growth, frequent mitotic figures • Self-limited, cured by excision • Must differentiate from a sarcoma

10. Nodular Fasciitis

11. Fibromatosis • Fibroproliferative lesions • Fibroblasts & Myofibroblasts • Infiltrative growth pattern • Tendency to recur • Desmoid - Infiltrative masses in abdominal, extra-abdominal & intra-abdominal • Palmar, plantar fibromatosis • Surgical excision

12. Fibromatosis

13. Fibrosarcoma • Malignant tumor of fibroblast origin • In adults, in lower extremities, upper extremities, trunk • Spindle cells in a herringbone pattern • Increased cellularity, high nuclear-cytoplasmic ratios • Must exclude other tumors which resemble fibrosarcoma - Peripheral nerve sheath tumor - Synovial sarcoma

14. Fibrosarcoma

15. Dermatofibroma • Benign fibrous histiocytoma • Usually in skin • Mixture of fibroblasts, myofibroblasts, histiocytes • Surgical excision

16. Dermatofibroma

17. Dermatofibrosarcoma Protuberans (DFSP) • Fibrohistiocytic tumor • Intermediate malignant potential • In skin & subcutis • Spindle cells in storiform pattern • Local recurrence • CD 34 • Transformation to fibrosarcoma • Surgical excision

18. Dermatofibrosarcoma Protuberans ( DFSP )

19. Malignant Fibrous Histiocytoma • Malignant soft tissue tumor with histocytic differentiation • Most common type of soft-tissue sarcoma • Most frequently encountered sarcoma post radiation therapy • In adults, in deep soft tissue - extremities & retroperitoneum • Marked pleomorphism, spindle cells, storiform, myxoid

20. MFH

21. Leiomyoma • Benign soft tissue tumor • Arising in subcutaneous tissue or blood vessel wall • Usually painful • Fascicles of regular smooth muscle cells

22. Leiomyoma

23. Leiomyosarcoma • Malignant soft tissue tumor • Arising in extremities of blood vessel wall • Necrosis, hemorrhage • Fascicles, nuclear atypia • High mitotic activity

24. Leiomyosarcoma

25. Rhabdomyosarcoma • Malignant tumor of striated muscle differentiation • In children & young adults • Several subtype - Embryonal - Alveolar - Botryoid - Pleomorphic

27. Embryonal Rhabdomyosarcoma • Most common in children, in head & neck • Most common subtype • Rhabdomyoblasts with cytoplasmic cross-striation

28. Embryonal rhabdomyosarcoma

29. Botryoid Rhabdomyosarcoma • Most common in hollow visceral organs - genitourinary tract • Polypoid, grape-like tumor masses • Scattered malignant cells in myxoid stroma

30. Botryoid rhabdomyosarcoma

31. Alveolar Rhabdomyosarcoma • In extremities • Fibrous septa with loose clusters of rounded cells in center - alveolar pattern

32. Alveolar rhabdomyosarcoma

33. Pleomorphic Rhabdomyosarcoma • In skeletal muscles of older persons, in thigh • Marked pleomorphism • Irregularly arranged cells • Multinucleated giant cells

34. Pleomorphic Sarcoma

35. Lipoma • Benign, well-circumscribed tumor of well-differentiated adipocytes • In adult, upper back, neck, shoulder • Usually subcutaneous, any site of adipose tissue • Most common type of benign soft tissue tumor • Resemble normal adipose tissue • Subtypes:angiolipoma, spindle cell lipoma

36. Lipoma

37. Liposarcoma • Second most common sarcoma in adults • In deep compartments of extremities & retroperitoneum • Lipoblasts • Several subtypes - Well differentiated/atypical lipoma - Myxoid / Round cell - Pleomorphic

38. Liposarcoma

39. Hemangioma • Benign lesion • Resemble normal blood vessels • Congenital or non-congenital • Most common in infants & children • Head & neck, internal organs - liver

41. Angiosarcoma • Malignant vascular tumor • Many locations: skin, soft tissue, breast, live, spleen • Irregular channels & atypical endothelial cells • CD31- endothelial cell marker

42. Angiosarcoma

43. Schwannoma • Benign tumor of neural differentiation - Schwann cells • In association with large nerve trunks • Head & neck, extremities • Antoni A • Antoni B -- Cellular area, palisaded nuclei • -- Less cellular area, myxoid background • S-100

44. Schwannoma

45. Synovial sarcoma • Malignant soft tissue tumor • Unknown origin- misnomer • Arising in region of a joint & other sites of deep soft tissue • Multilobular • Biphasic pattern - spindle cells - epithelial - like cells • t( X;18 )

46. Synovial sarcoma