Histopathology 2 - Bone tumours Flashcards
What is the preferred investigation for diagnosing bone tumours?
Core biopsy under radiological guidance
What is “shepherd’s crook deformity” a reference to?
Fibrous dysplasia involving the femoral head
Recall 4 tumour-like conditions of the bone that are not actually malignant
- Fibrous dysplasia
- Fibroma (can be ossifying/ non-ossifying)
- Reparative giant cell granuloma
- Simple bone cyst
How does osteochondroma mimic bone in appearance?
They have a cartilaginous surface overlying normal cortical + trabecular bone
In which bones is osteochondroma most likely to present?
Long bones
How will osteochondroma appear on XR?
“popcorn” pattern
Is a giant cell tumour of bone benign or malignant?
Borderline malignant
What is the typical age of presentation of osteochondroma?
20-40 years
What is the typical age of presentation of giant cell tumour of bone?
20-40 years
How do giant cell bone tumours appear under the microscope?
Osteoclasts on a background of ovoid cells
What are the 3 types of malignant bone tumour?
Osteosarcoma (bone-forming)
Chondrosarcoma (cartilage-forming)
Ewing’s sarcoma (undifferentiated mesenchymal)
Recall the typical age of presentation for each of the 3 types of malignant bone tumour
Osteosarcoma: <30 years
Chondrosarcoma: >40 years
Ewing’s sarcoma: <20 years
Recall the typical site affected for each of the 3 types of malignant bone tumour
Osteosarcoma: knee
Chondrosarcoma: pelvis/ proximal skeleton
Ewing’s sarcoma: long bones + pelvis
Recall the typical X ray appearance of each of the 3 types of malignant bone tumour
Osteosarcoma: Codman’s triangle
Chondrosarcoma: fluffy calcification
Ewing’s sarcoma: Onion-skinning of periosteum
What is a “Codman’s triangle”?
The triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone.
