Bone, Cartilage & Soft Tissue Tumors (Clinical)

Question 1

soft tissue lesions

Answer 1

lipoma, desmoid, soft tissue sarcoma

Question 2

staging a bone lesion

Answer 2

1st: x-ray entire affected bone, whole body bone scan, also CT of chest, abdomen and pelvis OR PET/CT. labs: serum protein electrophoresis/urine protein electrophoresis/serum free light chains, PSA if male

Question 3

multiple myeloma

Answer 3

common lymphoid malignancy, involves bone marrow, lytic lesions throughout skeleton. ~70 yo. pathologic fractures. cells often produce IgG

Question 4

B-cell lymphoma + marker

Answer 4

lymphomas: neoplasms composed of lymphocytes resembling noRmal stage of differentiation. B cell is most common type in adults, derived from clonal B cells.
CD20: ID’s B cells

Question 5

osteosarcoma

Answer 5

primary bone cancer

Question 6

lung adenocarcinoma

Answer 6

one of 4 major types of lung carcinoma. Mets early to bone, brain, liver. TTF1 positive. cytokeratin positive.

Question 7

childhood lesions of bone

Answer 7

osteochondroma, enchondroma, unicameral bone cyst, aneurysmal bone cyst, ewing sarcoma, osteosarcoma

Question 8

unicameral bone cyst (UBC)

Answer 8

benign, kids/YA. metaphysis of long bones, usually prox femur or humerus. pathologic fracture.
bone cortex eroded by cysts. increased interosseous pressure in bone.

Question 9

UBC pathology

Answer 9

cyst filled with clear fluid, lined with thin fibrous membrane. frequent fractures means old blood (hemosiderin) and granulation tissue may be present.

Question 10

aneurysmal bone cyst (ABC)

Answer 10

eccentric solitary expansile lesion. < 20 yo. metaphysis of long bones common. benign neoplasm with characteristic translocation.

Question 11

ABC histo

Answer 11

spongy, honecombed. cystic spaces filled with blood, but no endothelial cell lining. between blood filled spaces: fibrous septa, giant cells & immature bone/osteoid.

Question 12

cure ABC?

Answer 12

curretage, embolization/sclerotherapy

Question 13

giant cell tumor of bone

Answer 13

epiphysis, no mineralization.

Question 14

giant cell tumor of bone histo

Answer 14

cells look similar to ones around it. lytic, giant cells.

Question 15

osteosarcoma

Answer 15

aggressive. stellate cells. mineralization.

Question 16

ewing’s sarcoma

Answer 16

CD99 +. RECIPROCAL TRANSLOCATION: t(11;22)

Question 17

adult soft tissue masses

Answer 17

lipomas, soft tissue sarcomas, desmoid fibromatosis

Question 18

lipoma

Answer 18

large open cells. don’t need margins. glob of fat w thin membrane.

Question 19

desmoid fibromatosis

Answer 19

spindle cells. desmin +. beta catenin +.

Question 20

high-grade undifferentiated pleomorphic sarcoma

Answer 20

can’t tell cell of origin. radiology + wide excision

Question 21

osteochondroma

Answer 21

not concerning.

Question 22

chondrosarcoma

Answer 22

stage 1: curretage. stage 2: resect. cells have little matrix.

Question 23

DDx?

Answer 23

history of cancer, age, location, how aggressive, matrix production

Question 24

Stage patient (soft tissue)

Answer 24

CT of chest, abdomen, pelvis (look for mets), PET/CT

Question 25

stage patient (bone)

Answer 25

CT of chest, abd, pelvis (look for primary elsewhere), whole body bone scan, skeletal survey, labs

Question 26

biopsy techniques

Answer 26

avoid contaminating compartments! assume a sarcoma if isolated. communicate with path. < 3 cm probably lipoma. bigger = MRI.