Soft Tissue

Question 1

General principles (4):

Answer 1

• 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

Question 2

HHV 8 is associated with:

Answer 2

Kaposi’s sarcoma

Question 3

Ewing sarcoma and PNET tumor genetic changes:

Answer 3

t(11;22) EWS-FLI1 fusion

Question 4

Liposarcoma-myxoid and round cell type genetic changes:

Answer 4

t(12;16) FUS-DDIT3 fusion

Question 5

Synovial sarcoma genetic changes:

Answer 5

t(X;18) SS18-SSX fusion

Question 6

Rhabdomyosarcoma-alveolar type genetic changes:

Answer 6

t(2;13) PAX3-FOX01 fusion

Question 7

Extraskeletal myxoid chondrosarcoma genetic changes:

Answer 7

t(9;22) EWS-CHN fusion

Question 8

Best predictor of prognosis in soft tissue tumors:

Answer 8

Stage (location and size)

Question 9

Most common adult soft tissue tumor:

Answer 9

Lipoma

Question 10

Types of liposarcoma (2):

Answer 10

• Well-diferentiated

- Myxoid/roiund cell

Question 11

Liposarcoma - well-differentiated (3):

Answer 11

• Most common type of sarcoma
• Gross appearance same as lipoma
• MDM2 amplification (inhibits p53)

Question 12

Liposarcoma - myxoid/round cell (2):

Answer 12

• Intramuscular, most often the thigh

- Chicken-wire pattern of thin capillaries

Question 13

Max size of nodular fasciitis:

Answer 13

3 cm

Question 14

Myositis/panniculitis ossificans (2):

Answer 14

• Athletic adolescents and young adults

- Fibroblastic but later develops bone

Question 15

Superficial fibromatosis (3):

Answer 15

• Palmer fibromatosis
• Plantar fibromatosis
• Penile fibromatosis

Question 16

Deep-seated fibromatosis (3):

Answer 16

• Extra-abdominal
• Abdominal
• Intra-abdominal

Question 17

Palmer fibromatosis:

Answer 17

Dupuytren’s contracture

- Nodular thickening of palmar fascia; pucker skin and digit flexion contraction

Question 18

Plantar fibromatosis:

Answer 18

Irregular nodular thickening of plantar fascia

Question 19

Penile fibromatosis (3):

Answer 19

Peyronie’s disease

• Induration or mass on dorsolateral penis
• Can cause abnormal curvature of penis
• Can constrict urethra

Question 20

Abdominal deep-seated fibromatosis (2):

Answer 20

• Anterior abdominal wall

- Pregnancy or C-section

Question 21

Intra-abdominal deep-seated fibromatosis (2):

Answer 21

• Mesentery and pelvic walls

- Gardner syndrome

Question 22

Fibrosarcoma (2):

Answer 22

• Infiltrative fish-flesh with hemorrhage and necrosis

- Spindle cell with areas of herringbone pattern

Question 23

Three types of rhabdomyosarcoma (3):

Answer 23

• Embryonal
• Alveolar
• Pleomorphic

Question 24

Most common soft tissue sarcoma of childhood and adolescence:

Answer 24

Rhabdomyosarcoma

Question 25

Embryonal rhabdomyosarcoma (4):

Answer 25

• Majority of rhabdomyosarcomas
• Children < 10 years
• Soft, gray infiltrative mass
• Mimic skeletal muscle embryogenesis

Question 26

Embryonal rhabdomyosarcoma on EM:

Answer 26

Sarcomeres

Question 27

Embryonal rhabdomyosarcoma myogenic markers (3):

Answer 27

• MYOD1
• Myogenin
• Desmin

Question 28

Alveolar rhabdomyosarcoma (2):

Answer 28

• Early to mid-adolescence

- Deep muscles of extremities

Question 29

Pleomorphic rhabdomyosarcoma (3):

Answer 29

• Deep soft tissue of adults
• Very pleomorphic with rhabdomyoblasts
• Desmin, myogenin and MYOD1 positive

Question 30

Rhabdomyosarcoma with the best prognosis:

Answer 30

Sarcoma botryoides

Question 31

Leiomyoma:

Answer 31

Benign smooth muscle tumor

Question 32

Leiomyosarcoma markers (2):

Answer 32

• Positive: Smooth muscle actin and desmin

- Negative: MYOD1 and myogenin

Question 33

General epithelial marker (2):

Answer 33

• Cytokeratin

- EMA

Question 34

Skeletal muscle marker:

Answer 34

• MYOD1
• Myogenin
• Desmin
• Actin

Question 35

Nonepithelial tumor markers:

Answer 35

Vimentin

Question 36

Smooth muscle marker:

Answer 36

Desmin and actin