histology

Multiple Hereditary Exostosis

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)

 

Lateral Epicondylitis / Tennis Elbow

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)

Background

DefinitionKnee OCD MRI Cartilage Intact

 

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

 

Schwannoma

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

 

Elasto Fibroma Dorsi

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

 

 

 

Multiple Myeloma

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

 

Ewing Sarcoma

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

Chondrosarcoma

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

Nora lesion

 

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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