Bone

Question 1

What is osteoma?

Answer 1

Benign mature bony growths almost exclusively in bones formed in membrane(eg skull)

Question 2

What is the associated syndrome with multiple osteomas?

Answer 2

Gardner syndrome

Question 3

Common locations of osteoma?

Answer 3

Paranasal sinuses, skull vault, mandibular, nasal bones

Question 4

Pathology of osteoma?

Answer 4

(1)Ivory(dense bone lacks Haversian system) (2)Mature(like normal bone, with trabecular bone and central marrow) (3)Mixed

Question 5

Complications of osteoma?

Answer 5

Mucocele, mass effects(eg functional or cosmetic)

Question 6

Size of small enostoses(bone island)?

Answer 6

<2cm

Question 7

Common locations of enostoses?

Answer 7

Pelvis(particular giant bone island), femur, ribs

Question 8

What are worrying plain radiographic signs that you must differentiate bone islands from metastases?

Answer 8

Bone islands that are multiple, large, growing or red flags(eg pain at night, past malignancy history)

Question 9

Classic radiograph/CT features of enostoses?

Answer 9

Small round or oval foci of dense bone within medullary space. Radiating spicules at the margins blend with surrounding trabeculae.

Question 10

Common location of bone metastases?

Answer 10

• axial skeleton(highly vascuarlized hemopoietic red marrow), ribs, skull, pelvis, proximal humeri, proximal femur
• thoracic/lumbar spine more common than cervical spine
• distal to elbow/knee is rare(called acral metastasis, usually from primary lung neoplasm)
• in children, commonly axial/appendicular skeleton as wider distribution of red marrow

Question 11

Sensitive of radiograph to detect bone metastasis?

Answer 11

lesions are radiolographically apparent when 30-50% bone destruction present

Question 12

Usual primary sites for distal metastases(e.g. hands, feet)?

Answer 12

lung, kidneys

Question 14

What is Lodwick classification?

Answer 14

• describe the margins of a lucent/lytic bone lesion; determine aggressiveness and malignant potential
• grade 1 = geographical
• grade 1a: well-defined lesion with sclerotic rim
• grade 1b: well-defined lesion witihout sclerotic rim
• grade 1c: ill-defined lesion
• grade 2: multiple clustered foci of bone destruction of 2-5mm diameter each
• grade 3: multiple ill-defined foci of bone destruction <1mm diameter each