PATHOLOGIES

Question 1

osteoid osteoma

Answer 1

a benign bone tumour that usually develops in long bones. may have periostreal reaction. sclerosis

Question 2

giant cell tumour

Answer 2

a benign lytic lesion centered in the epiphysis but involving the metaphysis. symmetric and centrally located with growth. narrow ZOT. expansile, cortical thinning

Question 3

aneurysmal bone cyst

Answer 3

blood-filled lesion in the bone that tends to expand or grow. common in the knee, pelvis and spine. benign. cortical thinning

Question 4

chrondroblastoma

Answer 4

well-defined lytic lesions, thin sclerotic margins. eccentric epiphyseal located. may be associated with joint effusion. cortical thinning/endosteal scalloping, periosteal reaction, narrow ZOT.

Question 5

enchondroma

Answer 5

lytic lesion, with narrow ZOT, defined margins, metaphyseal region

Question 6

metastases

Answer 6

osteolytic lesion, cortical thinning, lucencies

Question 7

fibrous cortical defect

Answer 7

benign lytic lesion, typically located in the distal femur. typically occur in the metaphysis or diametaphyseal junction. no periosteal reaction

Question 8

osteosarcoma

Answer 8

cortical bone thinning/destruction, wide ZOT, aggressive periosteal reaction, Codman triangle. CT may be considered.

Question 9

Codman triangle

Answer 9

a lesion such as a tumour lifts the periosteum away from the bone. The small triangle of bone is seen at the advancing margin of the lesion.

Question 10

simple bone cyst

Question 11

osteochondroma

Answer 11

an overgrowth of cartilage and bone that happens at the end of the bone near the growth plate. cartilage cap. metaphysis of bone

Question 12

non-ossifying fibroma

Answer 12

lucent lesion, sclerotic rim, eccentrically located in metaphysis, narrow ZOT

Question 13

ewing sarcoma

Answer 13

wide zone of transition, poorly defined margin, periosteal reaction, may have bone expansion