Histo: Neoplastic Bone Disease Flashcards
Which part of the body is most commonly affected by neoplastic bone disease?
Around the knee joint
Outline some presenting features of neoplastic bone disease.
- Pain
- Swelling
- Deformity
- Fracture
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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
- Metaphyseal fibrous cortical defect/non-ossifying fibroma
- Reparative giant ell granuloma
- Ossifying fibroma
- 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
Which mutation causes fibrous dysplasia?
GNAS mutation Chr 20 q13 (mutation in a G-protein)
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
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?
- 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
What is an enchondroma and which bones tend to be affected?
- 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
What are two macroscopic features of benign bone tumours?
- Well demarcated
- May erode through the cortex of bone but does not burst through the cartilaginous surface
What are giant cell tumours? Where do they tend to be found and what is their histological appearance?
- Benign 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
What is the most common type of malignant bone tumour?
Metastases
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)
Describe the histological appearance of osteosarcoma.
- There are lots of malignant mesenchymal cells with or without bone and cartilage formation
NOTE: this can be stained for using ALP
How can osteosarcoma be classified?
- Site within the bone (intramedullary, intracortical, surface)
- Degree of differentiation
- Multicentricity
- Primary or secondary
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
List the histological subtypes of chondrosarcoma.
- Conventional (myxoid or hyaline)
- Clear cell (low grade)
- Dedifferentiated (high grade)
- Mesenchymal
NOTE: myxoid = composed of clear, mucoid substance
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 three types of soft tissue tumour.
- Liposarcoma
- Spindle cell sarcoma
- Pleomorphic sarcoma
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
