Bone & joints
Other tumors

Minor changes: 14 January 2021

Copyright: 2003-2021,, Inc.

PubMed Search: Adamantinoma[title]

Nat Pernick, M.D.
Page views in 2020: 6,262
Page views in 2021 to date: 390
Cite this page: Pernick N. Adamantinoma. website. Accessed January 22nd, 2021.
Definition / general
  • Rare malignant primary bone tumor with epithelial and mesenchymal elements
  • Common in tibia, usually shaft, usually young adults
  • 25% have symptoms for 5 or more years
  • Epithelial component derives directly from mesenchymal tissue and gradually increases in amount, may undergo sarcomatoid transformation (Am J Surg Pathol 2003;27:1530)
  • Osteofibrous dysplasia-like form: children and adolescents, relatively benign behavior, although may progress to classic adamantinoma; often recurs after curettage; no conspicuous nests of epithelial cells (Hum Pathol 1998;29:809)
  • Classic form: usually adults, more aggressive
Radiology description
  • Single or multiple lytic lesions of shaft (cortex or medulla) with marked surrounding sclerosis
Radiology images

Contributed by Dr. Mark R. Wick

MRI scan

Right distal tibia ankle xray



AFIP images

Lateral view of tibia

Adamantinoma and osteofibrous dysplasia

  • Excellent prognosis with complete excision; may have nodal or pulmonary metastases
Gross description
  • Poorly defined, firm and fibrous; may extend into adjacent soft tissue
Gross images

Contributed by Dr. Mark R. Wick


Microscopic (histologic) description
  • Squamous differentiation and keratin production is uncommon
  • Three forms:
    • Osteofibrous dysplasia-like form with scattered epithelial elements
    • Classic form with large groups of bland epithelial cells in clusters with peripheral palisading in fibrous stroma with haphazard osteoid deposition
    • Sarcomatoid transformation with highly pleomorphic cells, high mitotic count, deposition of osteoid and chondroid matrix, no epithelial features
Microscopic (histologic) images

Contributed by Dr. Mark R. Wick

In osteofibrous dysplasia

Keratin immunostain

Right distal tibia ankle

Contributed by Dr. Mark R. Wick

Various adamantinoma images

AFIP images

Adamantinoma images

Images hosted on other servers:

Quiz case

Positive stains
  • Keratin (epithelial and spindle cells)
Electron microscopy description
  • Spindle shaped epithelial tumor cells joined by desmosomesr
Differential diagnosis
  • Metastatic carcinoma: unusual below knee, older patients, more malignant cytology, no osteofibrous dysplasia-like areas
Additional references
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