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

  • Insidious 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

Adamantinoma, radiograph of adamantinoma of the tibia
Radiograph of adamantinoma of the tibia. Image by T-rex89 (Original) and Hellerhoff (cutting part of image and retouching), Wikimedia Commons, CC BY-SA 4.0.

X-ray

  • 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 is not diminished with fat suppression

Pathology

Adamantinoma, histology of adamantinoma at intermediate magnification
Histology of adamantinoma at intermediate magnification. Image by Nephron, Wikimedia Commons, CC BY-SA 3.0.

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

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.