Soft Tissue Tumors

Question 1

Firm tan papule in leg that is tender when shaved over.
Slow growing small and mobile nodule
Hemosiderin deposits, foamy cells, giant cells

Answer 1

Benign fibrous histiocytoma

Question 2

Large grey unencapsulated mass in musculature of a proximal extremity that exhibits pleomorphism, bizarre giant cells in storiform pattern
Occurs in adolescence
Aggressive

Answer 2

Malignant fibrous histiocytoma

Question 3

Solid, rapidly growing painful mass with cells that are immature resembling ganglion cells

Answer 3

Nodular fasciitis

Question 4

Swollen painful area that evolved into a hard well demarcated painless mass in adolescent athlete after trauma

Answer 4

Myosotis ossificans

Question 5

What are the X-ray findings of myosotis ossification at 3 weeks ?

Answer 5

Patchy flocculent radio densities in the periphery

Question 6

What is in the 3 zones of myosotis ossificans?

Answer 6

Center - fibroblasts
Intermediate - osteoblasts
Periphery - cancellous bone

Question 7

Unencapsulated, soft, fish-flesh mass in the retro peritoneum with hemorrhage and necrosis. Has herringbone hits pattern

Answer 7

Fibrosarcoma

Question 8

What is Dupuytren contracture found in?

Answer 8

The palmar variant of superficial fibromatosis

Question 9

What is peyronie disease a type of?

Answer 9

Superficial fibromatosis

Question 10

What arises in the metaphysis of the distal femur/proximal tibia in children over 2 and resolves spontaneously?

Answer 10

Fibrous cortical defect

Question 11

What shows up as elongated, sharply demarcated radiolucency surrounded by a thin rim of sclerosis?

Answer 11

Fibrous cortical defect

Question 12

What does a fibrous cortical defect look like?

Answer 12

Grey, yellow, brown tissue of fibroblasts and histiocytoma in pinwheel pattern

Question 13

At what age do fibrosarcomas occur?

Answer 13

Middle age and elderly

Question 14

This is a large tan-white hemorrhagic mass that arises in the metaphysis of long bones and pelvic flat bones.
On X-ray it is a permeati e and lyric lesion that extends into adjacent soft tissue
Produces collagen
Herringbone pattern is low grade
Spindle cells in storiform pattern is high grade

Answer 14

Fibrosarcomas

Question 15

What mutation is in fibrous dysplasia?

Answer 15

Somatic mutation of the gene for G proteins so there is excessive camp and hyperfunctioning cells

Question 16

Ground glass appearance on X-ray, intramedullary, expand and distort the bone, Chinese character trabeculae, lack osteoblastic rimming

Answer 16

Fibrous dysplasia

70% is monostotic

Question 17

Shepherd crook deformity
Craniofacial involvement
Diagnoses at earlier age
Intramedullary, chinese characters, disorganized growth plate, cystic degeneration and hemorrhage

Answer 17

Polyostotic fibrous dysplasia

Question 18

What is McCune Albright syndrome?

Answer 18

Polyostotic fibrous dysplasia with cafe au lait skin pigmentation and endocrinopathies

Question 19

What is the first sx of McCune Albright syndrome?

Answer 19

Precocious puberty

Question 20

What are the bone lesions like in McCune Albright syndrome?

Answer 20

They are unilateral with skin pigmentation on the same side

Question 21

Malignant small blue round cell tumor in medullary cavity in boys younger than 15

Answer 21

Ewing sarcoma

Question 22

Arise in diaphysis of long bones, Homer Wright rosettes, fever, anemia, increased ESR, leukocytosis, onion skin periosteal reaction

Answer 22

Ewing sarcoma

Question 23

Large red brown tumor in the metaphysis or epiphysis, multitudes tend giant cells and mononuclear cells that grow in synctium, necrosis, hemorrhage, hemosiderin depo.
X-ray: large, purely lyric and eccentric, erode into subchondral bone plate

Answer 23

Giant cell tumor - osteoclastoma

Question 24

If bone tumor in adult is from mets, what are the most likely cancers responsible?

Answer 24

Prostate
Breast
Kidney
Lungs

Question 25

If bone tumor in children is from mets, what is it most likely from?

Answer 25

Neuroblastoma, Wilms, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma

Question 26

Which primary cancers make lytic bone lesions?

Answer 26

Kidney
GI
Melanoma
Lung

Question 27

What primary cancer makes a blastic lesion?

Answer 27

Prostate adenocarcinoma

Question 28

What tumor is rapidly growing, multiloculated with blood filled spaces, in the metaphysis of long bones, and will see fluid fluid levels on MRI/CT?

Answer 28

Aneurysmal bone cyst