Soft Tissue Tumors

Question 1

What are soft tissue tumors?

Answer 1

mesenchymal proliferations that occur in the extraskeletal, nonepithelialized tissues of the body, excluding the viscera, coverings of the brain, and the lymphoreticular system

Question 2

What is sarcoma?

Answer 2

a connective tissue neoplasm, usually highly malignant, formed by proliferation of mesodermal cells

Question 3

What is a Lipoma?

Answer 3

benign, circumscribed, lobular, non-encapsulated mass, most are small and may grow for a long time

Question 4

What is a liposarcoma?

Answer 4

a malignant fat tissue tumor

• grossly looks like lipoma; but microscopically - cellular with atypical cells – lipoblasts are present

* lipoblasts have bizarre nucleus w/ vesicles of lipid in cytoplasm

Question 5

What is nodular fascitis?

Answer 5

1. a reactive proliferation
2. small benign fibrous proliferation on subcutis
3. young adults, rapid growth
4. found on arms! - flexor aspects of forearm

Question 6

What is Myositis ossificans?

Answer 6

1. reacitve proliferation
2. as a result of injury, entirely benign
3. often lower limb after blunt trauma
4. Woven bone is well-formed at the periphery but immature bone is at the center
5. the previous maturation in number 4 is not going to be present in malignancy- useful for distinguishing!

Question 7

What is fibromatosis superficial?

Answer 7

1. small lesion of hand - plantar is most common, bilateral, young male
2. lesion of penis - Peyronie dz - in association w/ other superficial
3. lesion of feet - in kids, also bilateral

Question 8

What is Duptyren’s Contracture?

Answer 8

1. fixed flexion contracture of the hand where the fingers bend towards the palm and cannot be fully extended
2. palmar aponeurosis becomes hyperplastic and undergoes contracture
3. progresses slowly, painless
4. tissue under skin thickens and shortens on palm

Question 9

What is deep fibromatosis?

Answer 9

1. Tumors are large, and local control can prove difficult
2. bland, spindle cell proliferation with no mitotic figures and no necrosis, despite the very large size of the tumor

Question 10

What is a fibrosarcoma?

Answer 10

1. a tumor of mesenchymal cell origin that is composed of malignant fibroblasts in a collagen background
2. painful
3. metaphysis of long bone and pelvis
4. men, lower extremities

5 Dxed in 4th decade commonly. if in kids – good prognosis!

6. . It can occur as a soft-tissue mass or as a bone tumor

Question 11

What is the difference of fibromas related to soft tissue and those of bone tumors?

Answer 11

Soft Tissue

1. the thigh and the posterior knee
2. large, painless mass deep to fascia and has an ill-defined margin

Question 12

What is this pattern called and what cancer is it found it in?

Answer 12

fibrosarcomas are said to demonstrate a “herringbone” patter

Question 13

What is a dermatofibroma?

Answer 13

1. a fibrohistiocytic tumor
2. growth of dermal dendritic histiocytic cells
3. found in legs and arms
4. firm nodules – yellow to brown
5. dimpling : tethering of the skin to the underlying fibrous tissue.

Question 14

What is a deramtofibrosarcoma protuberans?

Answer 14

1. relatively uncommon soft tissue neoplasm with intermediate- to low-grade malignancy
2. high recurrence rate
3. cutaneous malignancy that arises from the dermis and invades deeper subcutaneous tissue
4. gross path: umbilicated, somewhat irregular neoplasm (not dimpled!)

Question 15

What is Malignant Fibrous Histiocytoma?

Answer 15

1. spindled and rounded cells exhibiting a storiform
2. MFH accounts for 20-24% of soft-tissue sarcomas – most common soft tissue sarcoma of adult
3. common site of mets is lungs, rarely to bone and liver

Question 16

Describe what is happening here!

Answer 16

the transition from benign to malignan

Left: Dermatofibroma : bland histiocytic type cells interdigitate between normal collagen bundles.

Middle: dermatofibrosarcoma protuberans : greater cellularity, greater cellular atypia

Right :malignant fibrous histiocytoma (storiform)

Question 17

What is rhabdomyosarcoma?

Answer 17

1. tumor made up of cancerous muscle cells called rhabdomyoblasts
2. fish flesh appearance
3. common sites: Adjacent to the base of the skull (parameningeal); around the eye (orbital); other sites in the head and nec

Question 18

What cancer is this?

Answer 18

Rhabdo – usually made up of bizarre cells

Question 19

What is a leiomyoma?

Answer 19

1. benign smooth muscle – can be ubquitious since SM is found everywhere
2. uterus is a common site
3. reach quite a large size; in doing so they outgrow their blood supply and may undergo areas of necrosis with ultimate formation of one or more cysts (arrow).

Question 20

key points about uterine leiomyomas

Answer 20

Etiology unknown
Cells are clonal and are estrogen sensitive
Affect 25-40% of reproductive age women
Tend to regress after menopause
Most are asymptomatic
May be solitary or multiple
May be submucosal, intramural, or subserosal with pedunculation (on a stalk)

Question 21

What types of cells are seen in leiomyomas and leiomyosarcoma?

Answer 21

cigar shaped: has spindle shaped nuclei with blunt ends

Question 22

What are leiomyosarcoma?

Answer 22

1. malignant cancer of smooth muscle.
2. more common in the uterus, abdomen, or pelvis

Question 23

What is the difference btw the two pics?

Answer 23

Both are leiomyosarcoma.

Left: show two mitotic figures within one field, a very worrisome observation = low grade

Right: more bizarre cells are almost unrecognizable as having a smooth muscle origin = high grade

Question 24

Where do sarcomas like to go to?

Answer 24

lungs b/c tend to spread through the bloodstream (hematogenous spread) rather than through the lymphatic system

* Pulmonary metastases are a major cause of mortality for all sarcoma patients