Histopath: Bone disease

Question 1

What are the main benign bone tumours?

Answer 1

Fibrous dysplasia

Osteochondroma

Echondroma

Osteoid osteoma

Question 2

What are the main features of Fibrous dysplasia?

Answer 2

F>, mono-ostotic, age<30, PROXIMAL FEMUR/RIBS/tibia/ skull

X-ray = Soap-bubble osteolysis, Sheperds crook deformity if femur affected due to microfractures

Histo = marrow replaced by fibrous stroma + rounded trabecular bone (chinese letters)

Question 3

What are the main features of Osteochondroma?

Answer 3

10-20y, M>, ends of long bones - MOST COMMON BENIGN TUMOUR

X-ray = Bony protuberance w cartialge cap = MUSHROOM

Question 4

What are the main features of Echondroma?

Answer 4

Finger/ hands, middle aged + risk of malignant transformation

X-ray = POPCORN / COTTON WOOL CALCIFICATION, O ring sign, expansile

Question 5

What are the main features of Osteoid osteoma?

Answer 5

Adolescents, M>F

Dull pain at night - relieved by asprin

Question 6

What are the different malignant bone tumours?

Answer 6

Osteosarcoma

Chondrosarcoma

Ewings sarcoma

Giant cell tumour (borderline)

Question 7

What are the main features of Osteosarcoma?

Answer 7

MOST COMMON PRIMARY BONE CANCER

10-30y, M>, commonly knee -> pain + mass

Xray= elevated periosteum (codmans triangle) + mixed sclerotic lesions + SUNBURST APPEARANCE
Histo = malignant mesenchymal cells, stain for ALP+ve (IMPORTANT)

Question 8

What are the main features of Chondrosarcoma?

Answer 8

Cartilage producing, 40+y

Xray = FLUFFY CALCIFICATION + lyctic leisons

Question 9

What are the main features of Ewings sarcoma?

Answer 9

<20y, diaphysis/metaphysis of long bones

Xray - onion skinning of periosteum (MAIN)
Histo - SHEETS OF SMALL ROUND CELLS, CD99+ve, ALP-ve

Question 10

What are the main features of Giant cell tumour (borderline)?

Answer 10

KNee, 20-40y, F>

XRAY - SOAP BUBBLE APPEARANCE
HISTO - GIANT MULTINUCLEATE OSTEOCLASTS

Question 11

What are the different benign bone diseases?

Answer 11

Rheumatoid arthritis

Osteoarthritis

Ankylosing Spondylitis

Psoriatic arthritis

Osteoporosis

Reactive arthritis

Question 12

What is rheumatoid arthritis assocaited w/?

Answer 12

POSS

Periarticular erosions
Osteopaenia
Soft tissue swelling
Subluxations

Question 13

What is osteoarthritis associated w?

Answer 13

LOSS

Loss of joint space
Osteophytes
Subchondral cysts
Subcondral sclerosis

Question 14

What condition is associated w/ bamboo spine?

Answer 14

Ankylosing spondylitis

Question 15

What condition is associated w new fluffy bone and nail changes (onycholysis and nail pitting)?

Answer 15

Psoriatic arthritis

Question 16

What are the main features of osteoporosis?

Answer 16

Osteopaenai

Cortical thinning

Increased radiolucency

Question 17

What are the main features of reactive arthritis?

Answer 17

Seronegative (not associated w/ Rheumatoid factor)

HLA-B27 assc

Sacroiliac + knee joints

Question 18

What features are associated w reactive arthritis?

Answer 18

Keratoderma blennorrhagica, circinate balanitis, enthesitis