histology

Xray

Calcification

- central pattern

- often increased opacity compared with bone

Ossification

- peripheral pattern

- similar density to bone

AKA

Diaphyseal Aclasis / Multiple Osteochondromas

Definition

Heritable skeletal dysplasia

Epidemiology

AD with variable penetrance (96%)

Malignant Transformation

Incidence of malignant transformation much higher 

- 10% overall

- 1 % / year

Chondrosarcoma (CS) > Osteosarcoma (OS)

Incidence

Lateral : Medial 9:1

Epidemiology

4th & 5th decades

- M = F

- 75% dominant arm 

50% of regular tennis players

- especially > 2 hrs / week

Aetiology

Insertion pathology / Enthesopathy

Over-extension of the elbow with supination / pronation

Anatomy

Lateral epicondyle

- anconeus from posterior face

- ECRB and EDC from anterior face (CEO)

Definition

Osteochondritis Dissecans

- separation of avascular fragment of bone & cartilage

Epidemiology

M : F = 2:1

Mean age 18 years

- can present as young as 9

4:1000

Definition

Schwannoma

- benign tumour of nerve sheath

Epidemiology

Less common than neurofibroma

- occurs in adults

- can occur along any peripheral nerve

- also can occur along a nerve root

Usually a large nerve

More common in forearm

Seen in NF 2 

- acoustic Schwannoma

Condition

Strange scapular tumour

- typically bilateral 

- occurs in lat dorsi

Complain of lump which appears around scapula

Imaging

Looks like muscle on CT

Behaviour

Benign

Histology

Shows marked amount of elastin

Definition

Uncontrolled proliferation of single clone of plasma cells

Epidemiology

Most common malignant tumour of bone

Age 50-60

2-3 / 100 000

Pathology

Highly differentiated B lymphocytes

- associated with abnormality of protein synthesis

Usually bone marrow of entire skeleton involved

Principles

Treatment algorithm similar to OS

Overall prognosis similar to OS

- 70% long term survival

Definition

A malignant neoplasm composed of small round cells of uncertain histogenesis

Genetics

Recent data suggests it is of neuroepithelial derivation

- ? neuroectodermal cells

Definition 

Malignant cartilage producing tumour 

Epidemiology

20% of primary bone tumours

3rd most common

- 1 in 500 000

Relatively non-aggressive / usually Grade I

Average age 40

Male > Females

Two Distinct Types

1.  Primary Chondrosarcoma

Arises de novo

It was described in 1983 by Dr. Nora, and is sometimes called Nora's disease or Nora's lesion

Definition

Bizarre parosteal osteochondromatous proliferation 

Epidemiology

Rare lesion 

- occurs most commonly in the hands and feet

Adults in their 20's and 30's

Males = Females

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