Adamantinoma

Definition

  • Slow growing malignant tumour of the jaw & long bones
  • Probable epithelial origin

Epidemiology

  • Rare
  • 15-30 years of age
  • M>F
  • Of long bones 90% in diaphysis of anterior tibia
  • Rest in fibula or forearm bones

Clinical Features

  • Insiduous pain onset
  • Over many years
  • Intracortical stage IA sarcoma
  • 15% of patients get metastasis
  • 60% had history of trauma to limb months to years prior

Investigations

Xray

  • Extensive Soap Bubble appearance
  • Multiloculated & cystic lesion
  • Surrounding sclerosis, cortical thinning & expansion
  • May only involve anterior cortex initially
  • Similar to Ossifying fibroma

MRI

  • Low intensity T1 signal
  • Brighter on T2 that not diminished with fat suppression

Pathology

Gross

  • Well-circumscribed & rubbery nature
  • Greyish-white colour
  • Focal areas of haemorrhage & necrosis present

Microscopic

  • Biphasic appearance of
  • Spindle shaped collagen-producing cells
  • Alternating with sinewy cords or nests of epithelioid cells 
  • Spindle shaped cells probably reactive change only
  • Cells similar to fibrous dysplasia
  • Positive for Keratin

Treatment

  • Wide excision
  • Can have satellite lesions some distance from main mass
  • Locally invasive & 20% metastasis late in disease