Soft Tissue Flashcards
What is the most common sarcoma in children?
Rhabdomyosarcoma
What is the most common sarcoma in young adults?
Synovial sarcoma
What is the most common sarcoma in mid to late adults?
Undifferentiated pleomorphic sarcoma
Liposarcoma
What is the most common adult soft tissue tumor?
Lipoma
What is a conventional lipoma?
Thinly encapsulated yellow tumor
Lobules of mature fat
What are characteristic findings of a liposarcoma that differentiate it from a lipoma?
Atypical spindle cells
Cytoplasmic vacuoles, scallop nucleus
What is MDM2 amplification associated with?
Liposarcoma
What mutation is associated with a myxoid/round cell liposarcoma?
t(12;16) FUS-DDIT3 fusion protein
Where are myxoid/round cell liposarcomas usually located?
Intramuscular, most often the thigh
What is the most common location of nodular fasciitis?
Volvar forearm
What is nodular fasciitis?
Spindle cell tumor of fibroblasts
What is myositis ossificans?
Fibroblastic tumor that eventually develops bone
Occurs subcutaneously and in muscle
What is Palmer fibromatosis?
Nodular thicening of palmer fascia; puckers skin and digit flexion contraction
Dupuytrens contractions*
What is plantar fibromatosis?
Irregular of nodular thickening of plantar fascia
What is penile fibromatosis?
Peyronie’s disease
Induration of mass on dorsolateral penis
What mutations occur in deep-seated fibromatosis?
APC or B-catenin
What are the types of deep-seated fibromatosis?
Abdominal
Intra-abdominal
Extra-abdominal
What syndrome are intra-abdominal desmoid tumors associated with?
Gardner syndrome
What are fibrosarcomas?
Infiltrative fish-flesh with hemorrhage and necrosis
Spindle cell withaareas of herringbone pattern
Where do rhabdomyosarcomas usually occur?
Head/neck
GU tract (not kidney)
What rhabdomyosarcoma has the best prognosis?
Embryonal rhabdomyosarcoma
What is the sarcoma botryoides variant of embryonal rhabdomyosarcoma?
Clust of grapes protrudes into lumen
Cambium layer: submucosal hypercellular layer
What three markers are associated with rhabdomyoblasts?
MYOD1
Myogenin
Desmin
What are tadpole cells and strap cells?
Striated cells characteristic of rhabdomyosarcoma
What is an alveolar rhabdomyosarcoma?
Fibrous speta divide tumor into alveolar-like spaces centrally containing discohesive cells while peripheral cells stick to wall
What translocation is associated with alveolar rhabdomyosarcoma?
t(2;13) or t(1;13)
What is a leiomyoma?
Benign smooth muscle tumor
Bland smooth muscle in fascilcles
Most common tumor in the uterus
What is a leiomyosarcoma?
White masses
Malignant spindle cells
Positive for smooth muscle actin and desmin
What is a synovial sarcoma?
Biphasic tumor
Typically around large joints
Cytokeratin positive
What what translocation is associated with synovial sarcoma?
t(X;18)
STY-SSX1 or STY-SSX2 fusion
What is an undifferentiated pleomorphic sarcoma?
Group of aggressive neoplasms
Diagnosis of exclusion
