Histopathology - Neoplastic Bone Disease Flashcards
What are some features of benign bone diseases on XR?
- No periosteal reaction
- Thick endosteal reaction
- Regular bone formation
- Intraosseous + regular calcification
What are some features of malignant bone disease on XR?
- Acute periosteal reaction (Codman’s triangle, Onion skin, Sunburst)
- Brioad border between lesion + normal bone
- Varied bone formation
- Extraosseous + irregular calcification
What is the epidemiology of an Osteosarcoma?
- Adolescence
- V. rare (60% less rare than lung cancer)
What bone is characteristically affected in Osteosarcoma?
Knee (60%)
What is seen on histiology for Osteosarcoma?
- Malignant mesenchymal cells
- ALP +ve
- Replacement of bone marrow with trabecular bone
What is the XR appearance of Osteosarcoma?
- Elevated periosteum (Codman’s triangle)
- Sunburst appearance
What is the epidemiology of Chondrosarcoma?
> 40yrs
What bones are typically affected by Chondrosarcoma?
- Axial skeleton
- Femur
- Tibia
- Pelvis
What is seen on histology of Chondrosarcoma?
- Malignant chondrocytes (proliferation of cartilage)
What is seen on XR of Chondrosarcoma?
- Lytic lesino with FLUFFY CALCIFICATION
What are the malignant bone cancers?
- Osteosarcoma
- Chondrosarcoma
- Ewing’s sarcoma
- Giant cell
What is the epidemiology of Ewing’s sarcoma?
- <20yrs
- HIGHLY MALIGNANT
What bones are commonly affected in Ewing’s sarcoma?
- Long bones
- Pelvis
What are the histological features of Ewing’s sarcoma?
- Sheets of SMALL ROUND CELLS
- CD99 +VE
- T 11:22 translocation
What is seen on XR of Ewing’s sarcoma?
- ONION SKINNING of periosteum
What is the epidemiology of giant cell cancer?
- 20-40yrs
- F>M
What bones are commonly affected in giant cell cancer?
- Knee (epiphysis)
What are the histological features of giant cell cancer?
- Osteoclasts + stromal cells
- Soap bubble appearance
- Giant multi-nucleate osteoclasts
What is seen on XR of giant cell cancer?
- Lytic/lucent lesions right up to articular surface
What are the benign bone tumours?
- Osteoid Osteoma
- Osteoma
- Enchondroma
- Osteochondroma
- Fibrous dysplasia
- Simple bone cyst
- Osteoblastoma
What is the epidemiology of Osteoid Osteoma?
- Adolescent
- M:F = 2:1
What bones are typically affected in Osteoid Osteoma?
- Tibia diaphysis
- Proximal femur
What are the special features of Osteoid Osteoma?
- Small benign bone forming lesion
- Night pain relieved by aspirin
What is seen on histology of Osteoid Osteoma?
- Normal bone
- Arises from Osteoblasts
What is seen on XR of Osteoid Osteoma?
- Central nidus (luscent)
- Sclerotic rim (opaque)
- Bull’s eye
What is the epidemiology of Osteoma?
- Middle age
What bones are commonly affected by Osteoma?
- Head
- Kneck
What are the special features of Osteomas?
- Bony outgrowths attached to normal bone
Gardner Syndrome:
- GI polyps
- Multiple Osteomas
- Epidermoid cysts
What is seen on histology of Osteoma?
Normal bone
What is the epidemiology of Enchondroma?
- Middle age
What bones are typically affected by Echondroma?
- Hands (43%)
What bones are typically affected by Echondroma?
- Hands
What are the special features of Echondroma?
- Benign tumours of cartilage
- Ollier’s syndrome = Multiple echondromas
- Maffuci’s syndrome = Multiple echondromas + haemangiomas
What is seen on histology for Echondromas?
- Normal cartilage
- Calcified matrix
What is seen on XR for Echondromas?
- Lytic lesion
- Cotton wool calcifications
- Expansile
- O ring sign
What is the epidemiology of Osteochondromas?
- Adolescent
- Most common benign tumour
What bones are commonly affected in Osteochondromas?
- Metaphysis of long bones near tendon attachment sites
What are the special features of Osteochrondromas?
- Cartilage capped bony outgrowth
- Diaphyseal aclasis/hereditary multiple exostoses = mulitple exostoses + short stature + bone deformities
What is seen on hitsology of Osteochondromas?
- Cartilage capped mushroom bony outgrowth
What is seen on XR of Osteochondromas?
- Well defined bony protuberance from bone
- Cartilage capped bony spur on surface of bone “mushroom” on XR
What is the epidemiology of fibrous dysplasia?
- F>M
- Middle age
What bones are most commonly affected in fibrous dysplasia?
- Femur
- Ribs
What are the special features of fibrous dysplasia?
- A bit of bone is replaced by fibrous tissue
McCune-Albright Syndrome:
- Polyostotic dysplasia
- Cafe au lait spots
- Precocious puberty
What is seen on histology for fibrous dysplasia?
- Chinese letters (misshapen bone trabeculae)
What is seen on XR of fibrous dysplasia?
- Soap bubble osteolysis
- Shepherd’s crook deformity
Which bones are commonly affected in a simple bone cyst?
- Humerus
- Femur
What is the special feature of a simple bone cyst?
- Fluid filled unilocular
What is seen on XR for a simple bone cyst?
- Lytic
- Well defined
What is a special feature of Osteoblastoma?
- Similar to osteoid osteoma (small beningn bone forming lesion, night pain releived by aspirin)
What is seen on XR for Osteoblastoma?
- Speckled mineralisation
