MSS3

Question 1

The following genetic syndromes are associated with what soft tissue tumors?
Neurofibromatosis Type I
Gardner
Li-Fraumeni
Osler-weber-Rendu

Answer 1

Neurofibromatosis Type I: neurofibroma, malignant schwannomma
Gardner: fibromatosis
Li-Fraumeni: soft tissue sarcomas
Osler-weber-Rendu: telangiectasia

Question 2

What age is each each of the following sarcomas associated with?
Rhabdomyosarcoma
synovial sarcoma
Liposarcoma or undifferentiated sarcoma

Answer 2

Rhabdomyosarcoma- childhood
synovial sarcoma– young adulthood
Liposarcoma or undifferentiated sarcoma–later adult

Question 3

What are the prognostic factors of a soft tissue sarcoma?

Answer 3

Grade, size, depth and stage
Grading: based on degree of differentiation, average number of mitosis, extent of necrosis
Size: Greater/less than 5
depth: above or under fascia, stage
superficial locations have better prognosis

Question 4

What is the most common soft tissue tumor of adulthood? Are they usually solitary or occur in multiples?

Answer 4

Lipoma. Genrally Solitary, if multiple suggests hereditary syndrome. Most are mobile, slowly enlarging and painless

Question 5

What are characteristics of a lipoma?

Answer 5

Lipomas are soft, yellow, well encapsulated. Histology: mature white fat cells w/ no pleomorphism

Question 6

What is a common sarcoma of adulthood of proximal extremeties and retroperitoneum? What predicts the behavior of this sarcoma?

Answer 6

Liposarcoma is a common sarcoma age 40-60. Histology: Well-differentiated, myxoid/round or pleomorphic.
Histology predicts behavior:
- well-differentiated: slow growing (amplification of 12q14-q15, containing MDM2)
- Myxoid/round: intermediate (hypercellular areas)
- Pleomorphic: aggressive

Question 7

What are the histological characteristics of lipoblasts?

Answer 7

Lipoblasts are smaller, vaculated bubbles. Nucleus is closer to the center (indented and dark). Hallmark of liposarcoma

Question 8

what are the histological characteristics of myxoid LPS?

Answer 8

Myxoid: pale stroma with hypercellularity around vasculature

Question 9

What are pseudosarcomatous Proliferations?

Answer 9

Reactive non-neoplastic lesions that develop in response to some form of local trauma or idiopathic. They develop suddently and grow rapidly and can mimic sarcomas ( hypercellular, mitotic activity)

Question 10

What are the types of pseudosarcomatous proliferations?

Answer 10

Nodular Fasciitis: deep dermis, subcutis or muscle
Myositis Ossificans: proximal extremities: presence of metaplastic bone that eventually ossifies and becomes filled with marrow.

Question 11

What are some common locations of superficial fibromatosis?

Answer 11

Palmar, plantar, penile

Question 12

What are desmoid tumors?

Answer 12

Deep seated fibromatosis that behaviors somewhere between benign fibrous tumors and low grade fibrosarcomas. Some are associated with Gardner syndrome. Occur in teens to 30s

Question 13

What are Fibrosarcomas?

Answer 13

malignant sarcomas that are ocmposed of mostly fibroblasts. Occur in deep tissues of thigh, knee and retroperitoneum. Histology: sheaths of spindle cells that are pleomorphic. Aggressive tumors that recur in >50% of cases.

Question 14

What is is a leiomyoma?

Answer 14

Smooth muscle tumor. Uterine leiomyomas= fibroids (most common neoplasm).

Question 15

Leimyosarcoma

Answer 15

smooth muscle sarcoma. Usually of the skin and deep soft tissues of the extremities and retroperitoneum. Large lesions in retroperitoneum cannot be entirely excised

Question 16

What is the most common soft tissue sarcoma of childhood and adolescence? Where are the lesions found?

Answer 16

Rhabdomyosarcoma. Most commonly in head, neck or GU tract

Question 17

What are the three types of Rhabdomyosarcoma?

Answer 17

Embryonal, Alveolar, Pleomorphic
Embryonal: common in very young children (head, neck, GU tract). Variants: botryoides (grape-like). Histology: small round and blue cells.
Alveolar: deep soft tissue of extremities, usually 10-25yo. Histology: alveolar pattern

Question 18

Where do Synovial Sarcomas commonly occur? What is the characteristic genetic finding?

Answer 18

Deep soft tissues, usually around knee. T(x;18) (p11, q11). Histologically: monophasic (spindle cells) or bi phasic (spindle and gland like spaces).
TX: aggressive limb sparing surgery and chemo