Histo: Neoplastic Bone Disease Flashcards
Which part of the body is most commonly affected by osteosarcoma?
Knee 60%
Outline some presenting features of neoplastic bone disease.
- Pain
- Swelling
- Deformity
- Fracture
What type of biopsy is often used for diagnosing neoplastic bone disease?
Needle biopsy using a Jamshidi needle under CT or US guidance
List some tumour-like conditions of the bone.
- Fibrous dysplasia
- Simple bone cyst
What is fibrous dysplasia?
- Condition in which fibrous tissue develops in place of normal bone tissue
- Can occur in any bone but ribs and proximal femur is most common
- Tends to affect patients < 30 years
- Causes soap bubble osteolysis on X-ray
Which eponymous syndrome is characterised by polyostotic fibrous dysplasia?
McCune Albright Syndrome - polyostotic fibrous dysplasia + endocrine problems + rough border café-au-lait spots
Describe the histological appearance of fibrous dysplasia.
The marrow is replaced by fibrous stroma with rounded trabecular bone (‘Chinese letters’)
Describe the X-ray appearance of fibrous dysplasia of the femoral head.
Shepherd’s crook + soap bubble osteolysis
List three types of cartilaginous benign bone tumour.
- Osteochondroma
- Enchondroma
- Chondroblastoma
List three types of bone-forming benign bone tumour.
- Osteoid osteoma
- Osteoma
- Osteoblastoma
What are osteochondromas and which bones tend to be affected? Histological and X-ray findings?
- A benign overgrowth of cartilage and bone that tends to happen at the ends of long bones
- They mimic normal tubular bone as they have a cartilaginous surface overlying normal trabecular bone
Mushroom bony outgrowth on histology
bony protuberance from bone on X-ray
What is an enchondroma and which bones tend to be affected?
X-ray finding?
- A cartilaginous proliferation within the bone
- Most tend to be found in the hands and can cause pathological fractures
- X-ray may show popcorn calcification
Ends - end of arms - hands
Xray findings of benign vs malignant bone disease?
Benign - regular bone formation, intraossesous and regular calcification
Malignant - varied bone formation, extra osseous and irregular calcification
What are giant cell tumours? Where do they tend to be found and what is their histological appearance?
- Benign/borderline malignant tumour of the bone characterised by the presence of lots of osteoclasts (giant cells)
- They tend to be found at the ends of long bones
- It has a lytic appearance on X-ray
- Histology shows many osteoclasts on a background of spindle/ovoid cells and soap bubble
What is the most common and second most common type of malignant bone tumour?
Metastases and then osteosarcoma
Which cancers in adults tend to spread to the bone?
- Breast
- Prostate
- Lung
- Kidney
- Thyroid
Which cancers in children tend to spread to the bone?
- Neuroblastoma
- Wilm’s tumour
- Osteosarcoma
- Ewing’s sarcoma
- Rhabdomyosarcoma
List three types of malignant bone tumour.
- Osteosarcoma
- Chondrosarcoma
- Ewing’s sarcoma/PNET
What is an osteosarcoma?
- Malignant bone-forming tumour of the bone that mainly occurs at the ends of long bones
- Tends to occur at age 10-30 years
Describe the X-ray appearance of osteosarcoma.
- Usually metaphyseal
- Lytic
- Elevated periosteum (Codman’s triangle)
- sunburst appearance
Describe the histological appearance of osteosarcoma + blood test?
- There are lots of malignant mesenchymal cells with or without bone and cartilage formation
NOTE: this can be stained for using ALP
High ALP
What is a chondrosarcoma?
- Malignant cartilage producing tumour
- Tends to occur in patients aged > 40 years
Describe the X-ray appearance of chondroscarcoma.
Lytic with fluffy calcification
What is an Ewing’s sarcoma?
- Highly malignant small round cell tumour
- Occurs in people < 20 years old
Describe the X-ray appearance of Ewing’s sarcoma.
- Onion skinning of the periosteum
- Lytic with or without sclerosis
Describe the histological appearance of Ewing’s sarcoma.
Sheets of small round cells
Which genetic abnormality is associated with Ewing’s sarcoma?
Chromosomal translocation 11:22 (EWSR1/FLI1) (q24:q12)
Define soft tissue tumour.
Mesenchymal proliferations which occur in the extra-skeletal, non-epithelial tissues of the body - excluding meninges and lymphoreticular system
List some special diagnostic techniques used to diagnose soft tissue tumours.
- Immunohistochemistry
- Electron microscopy
- Cytogenetic
- FISH
- RT-PCR
List some bad prognostic factors for soft tissue tumours.
- Size
- Depth
- Grade
- Vascular invasion
- Ploidy
Most common benign bone tumour?
Osteochondroma
What bones does ewing’s sarcoma usually affect and what age group?
Long bones and pelvis, <20y
What age group for each of these:
Osteosarcoma
Ewing’s sarcoma
Chondrosarcoma
Osteosarcoma - children
Ewing’s sarcoma - <20
Chondrosarcoma - >40
Which bone tumour has the worst prognosis?
Ewing’s sarcoma as it is highly malignant
