Histopathology 2: Neoplastic Bone Disorders

Question 1

X-ray: Codman’s Triangle at end of long bones
Histology: Malignant mesenchymal cells

Diagnosis?

Answer 1

Osteosarcoma

Question 2

X-ray: Lytic lesions with fluffy calcification
Histology: Malignant chondrocytes

Diagnosis?

Answer 2

Chondrosarcoma

Question 3

X-ray: Onion skinning of periosteum
Histology: Sheets of small round cells
Karyotype: shows t(11;22)

Diagnosis ?

Answer 3

Ewing’s sarcoma

Question 4

X-ray: Lytic appearance in the epiphysis of knee
Histology: Giant cells look like osteoclasts, spindle/ovoid cells

Diagnosis?

Answer 4

Giant cell tumour

Question 5

X-ray: Soap bubble osteolysis, Shepherd’s crook deformity
Histology: Chinese letters

Diagnosis ?
Associated syndrome ?

Answer 5

Fibrocystic dysplasia

Albright syndrome

Question 6

List the triad of features Albright syndrome?

Answer 6

• Polyostotic dysplasia
• cafe au lait spots
• Precocious puberty

Question 7

X-ray: Mushroom protuberance from Bone
Histology: Cartilage capped bony outgrowth

Diagnosis?

Answer 7

Osteochondroma

Question 8

X-ray: popcorn calcification
Histology: Proliferation of cartilage

Diagnosis ?

Answer 8

Enchondroma

Question 9

X-ray: Bulls eye appearance of radioleucent nidus with sclerotic rim
Histology: normal bone arising from osteoblasts

Diagnosis ?

Answer 9

Osteoid Osteoma

Question 10

Which benign bone tumour causes pain at night which is relieved by Aspirin ?

Answer 10

Osteoid osteoma

Question 11

In which syndrome do you get Osteomas, GI polyps and epidermoid cysts ?

Answer 11

Gardner syndrome

Question 12

Which bone tumour shows speckles mineralisation and is similar to osteoid osteoma ?

Answer 12

Osteoblastoma

Question 13

Parts of the bone

Answer 13

long part = diaphysis
end part = epiphysis

outside - inside = periosteum - cortex - medulla

Question 14

list 5 tumour- like condition

Answer 14

fibrous dysplasia 
metaphysial fibrous cortical defect/ non-ossifying fibroma
reparative giant cell granuloma 
ossifying fibroma 
simple bone cyst

Question 15

Features of fibrous dysplasia

Answer 15

F>M
ribs and proximal femur common
‘soap bubble osteolysis’ on x-ray
McCune Albright syndrome - associated with endocrine problems and cafe au lait spots
mutation in G protein
Chinese letters - marrow replaced with fibrous stroma
fibrous dysplasia in femoral head = shepherd’s crook
microfractures lead to a change in shape

Question 16

name 3 cartilagenous bone tumours

Answer 16

osteochondroma
echondroma
chondroblastoma

Question 17

name 3 bone forming benign bone tumours

Answer 17

osteoid osteoma
osteoblastoma
osteoma

Question 18

features of osteochondroma

Answer 18

ends of long bones
young
males
cartilagenous surface overlying normal trabecular bone

Question 19

features of echondroma

Answer 19

cartilagenous proliferation within the bone
hands and feet
rarely ends of long bones
popcorn calcification

Question 20

two key macroscopic features of benign bone tumours

Answer 20

well demarcated

may erode through the cortex of the bone but does not burst through the cartilagenous surface

Question 21

features of giant cell tumours

Answer 21

site = epiphysis with metaphysial extension
20-40 yrs
F>M
lytic on x-ray
osteoclasts on a background of spindle/ovoid cells

Question 22

what adult cancers commonly spread to the bone

Answer 22

breast
prostate
lung
kidney
thyroid

Question 23

what child cancers commonly spread to the bone

Answer 23

neuroblastoma 
wilm's tumour
osteosarcoma 
ewing's sarcoma 
rhabdomyosarcoma

Question 24

3 types of malignant bone tumour

Answer 24

1 - osteosarcoma - forms bone
2 - chondrosarcoma - forms cartilage
3 - ewings sarcoma/ PNET - undifferentiated mesenchymal

Question 25

features of osteosarcoma

Answer 25

age 10-30 
end of long bones 
jaw of older patients 
M>F
most common bone sarcoma 
X ray - metaphysical, lytic, permeatuve, elevative periosteum (Codman's triangle)
histology: malignant mesenchymal cells with or without bone and cartilage formation 
poor prognosis

Question 26

features of chondrosarcoma

Answer 26

produces cartilage
>40yrs
axial skeleton, pelvis, proximal femur, proximal tibia
x-ray - lytic with fluffy calcifications
malignant chondrocytes on hist.

Question 27

features of ewings sarcoma (PNET)

Answer 27

highly malignant small round cell tumour
<20 yrs
diaphysis/metaphysis of long bones, pelvis
x-ray - onion skinning of the periosteum, lytic or without sclerosis
hist - sheet of small round cells
11;22 chr translocation

Question 28

list types of soft tissue tumours

Answer 28

liposarcoma
spindle cell sarcoma
pleomorphic sarcoma

Question 29

features of liposarcoma

Answer 29

myxoid appearance

Question 30

how can we diagnose soft tissue tumours

Answer 30

immunohistochemistry 
EM 
cytogenetics
FISH 
M-FISH

Question 31

benign vs malignant bone disease

Answer 31

benign:

• no periosteal reaction
• thick endostial reaction
• well developed bone formation
• intraosseous and even calcification

malignant:

• acute periosteal reaction - codmans triangle, onion skin, sunburst
• borad border between lesion and mortal bone
• varied bone formation
• extra osseous and irregular calcification