Soft Tissue Flashcards
General principles (4):
- Benign outnumber malignant
- Metastasis tend to be blood borne to lungs, liver and bone
- Lower extremity, especially thigh
- Bone involved by direct extension or metastasis
HHV 8 is associated with:
Kaposi’s sarcoma
Ewing sarcoma and PNET tumor genetic changes:
t(11;22) EWS-FLI1 fusion
Liposarcoma-myxoid and round cell type genetic changes:
t(12;16) FUS-DDIT3 fusion
Synovial sarcoma genetic changes:
t(X;18) SS18-SSX fusion
Rhabdomyosarcoma-alveolar type genetic changes:
t(2;13) PAX3-FOX01 fusion
Extraskeletal myxoid chondrosarcoma genetic changes:
t(9;22) EWS-CHN fusion
Best predictor of prognosis in soft tissue tumors:
Stage (location and size)
Most common adult soft tissue tumor:
Lipoma
Types of liposarcoma (2):
- Well-diferentiated
- Myxoid/roiund cell
Liposarcoma - well-differentiated (3):
- Most common type of sarcoma
- Gross appearance same as lipoma
- MDM2 amplification (inhibits p53)
Liposarcoma - myxoid/round cell (2):
- Intramuscular, most often the thigh
- Chicken-wire pattern of thin capillaries
Max size of nodular fasciitis:
3 cm
Myositis/panniculitis ossificans (2):
- Athletic adolescents and young adults
- Fibroblastic but later develops bone
Superficial fibromatosis (3):
- Palmer fibromatosis
- Plantar fibromatosis
- Penile fibromatosis
Deep-seated fibromatosis (3):
- Extra-abdominal
- Abdominal
- Intra-abdominal
Palmer fibromatosis:
Dupuytren’s contracture
- Nodular thickening of palmar fascia; pucker skin and digit flexion contraction
Plantar fibromatosis:
Irregular nodular thickening of plantar fascia
Penile fibromatosis (3):
Peyronie’s disease
- Induration or mass on dorsolateral penis
- Can cause abnormal curvature of penis
- Can constrict urethra
Abdominal deep-seated fibromatosis (2):
- Anterior abdominal wall
- Pregnancy or C-section
Intra-abdominal deep-seated fibromatosis (2):
- Mesentery and pelvic walls
- Gardner syndrome
Fibrosarcoma (2):
- Infiltrative fish-flesh with hemorrhage and necrosis
- Spindle cell with areas of herringbone pattern
Three types of rhabdomyosarcoma (3):
- Embryonal
- Alveolar
- Pleomorphic
Most common soft tissue sarcoma of childhood and adolescence:
Rhabdomyosarcoma
Embryonal rhabdomyosarcoma (4):
- Majority of rhabdomyosarcomas
- Children < 10 years
- Soft, gray infiltrative mass
- Mimic skeletal muscle embryogenesis
Embryonal rhabdomyosarcoma on EM:
Sarcomeres
Embryonal rhabdomyosarcoma myogenic markers (3):
- MYOD1
- Myogenin
- Desmin
Alveolar rhabdomyosarcoma (2):
- Early to mid-adolescence
- Deep muscles of extremities
Pleomorphic rhabdomyosarcoma (3):
- Deep soft tissue of adults
- Very pleomorphic with rhabdomyoblasts
- Desmin, myogenin and MYOD1 positive
Rhabdomyosarcoma with the best prognosis:
Sarcoma botryoides
Leiomyoma:
Benign smooth muscle tumor
Leiomyosarcoma markers (2):
- Positive: Smooth muscle actin and desmin
- Negative: MYOD1 and myogenin
General epithelial marker (2):
- Cytokeratin
- EMA
Skeletal muscle marker:
- MYOD1
- Myogenin
- Desmin
- Actin
Nonepithelial tumor markers:
Vimentin
Smooth muscle marker:
Desmin and actin
