management

Definition

Malignant tumour of striated muscle

Juvenile variety arises from mesenchyme

Epidemiology

Most common malignant ST Tumour in children (< 15 years)

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

Definition

Cystic structure lined by a mature capsule of dense fibrous tissue

- contains thick viscous fluid with a high mucopolysaccharide content

- fluid is a myxoid degeneration of synovial fluid

Epidemiology

Most common in young females

- peak age 15-30

- F:M = 3:1

Most common tumour in hand (2/3)

Aetiology

Unclear

Epidemiology

Uncommon

- 4% OS

Females more common 

- similar to GCT

NHx

Less aggressive locally

- less metastasis

- size / location & duration of symptoms don't correlate with outcome

Arise from cortex of bone / periosteum

- parosteal 

- periosteal

- high grade juxtacortical

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

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

Definition

Metaphyseal Enchondroma

Site

Arise from the metaphyseal cortex of long bones

- most common in the proximal humerus

Histology

Difficult to DDx from Chondrosarcoma

Masses of cartilage nestling in a shallow crater in the periphery of the cortex

NHx

Don't ossify

- remain as immature cartilage

AKA

Non Ossifying Fibroma

Definition

A hamartomatous defect in the metaphyseal cortex of skeletally-immature adolescents

Fibrous cortical defect 

- < 2cm in diameter

Non ossifying fibromas 

- > 2cm

Aetiology

Definition

Benign lesion with a wide spectrum of behavior characterized by stromal cells and giant cells

Epidemiology

Common

- 20% of benign tumours

More common females

- F:M = 1.5:1

- most tumours M>F

Usually patient in 20's

- usually after skeletal maturity

- 3% < epiphyseal closure

Definition

Langerhan's Cell Histiocytosis

- non-neoplastic disorder

- characterised by infiltration by histiocytic cells (Monocyte / macrophage lineage)

Group of granulomatous inflammatory processes of unknown aetiology

- involve the reticuloendothelial component of the bone marrow, parenchymal organs, and skin

Types 

E - H - L