Osteochondroma

A benign lesion derived from aberrant cartilage from the perichondral ring; the most common benign bone tumour

Aetiology

  • Common in adolescents and young adults (10-20 years)
  • Can be caused by tramua
  • Can be solitary or multiple
    • Multiple osteochondromata can occur as an autosomal dominant hereditary disorder - Multiple Hereditary Exostosis (MHE)

Pathophysiology

  • Produces a bony outgrowth on the external surface with a cartilaginous cap

Clinical presentation

  • Painless, hard lump
  • Commonly occur near the knee - distal femur/proximal tibia
  • May be symptoms with activity - pain from tendons, numbness from nerve compression

Investigations

  • Imaging (x-ray, MRI) - cartilage capped ossified pedicle
notion image

Management

  • Close observation - small risk of malignant transformation (<1%) so any lesion growing in size or causing pain may require excision
  • In MHE there are more tumours so higher change of malignancy