Bone
Bone forming tumors (not osteosarcoma)
Adamantinoma

Author: Nat Pernick, M.D. (see Authors page)

Revised: 25 October 2016, last major update August 2013

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Adamantinoma[title]
Cite this page: Adamantinoma . PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/boneadamantinoma.html. Accessed December 8th, 2016.
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

Images hosted on Pathout server:

MRI scan - contributed by Dr. Mark R. Wick

Right distal tibia ankle xray - contributed by Dr. Mark R. Wick

Tibia - contributed by Dr. Mark R. Wick

Xray - contributed by Dr. Mark R. Wick

Lateral view of tibia

Adamantinoma and osteofibrous dysplasia

Treatment
  • 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

Images hosted on Pathout server:

Tibia - contributed by Dr. Mark R. Wick

Micro 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
Micro Images

Images hosted on Pathout server:

In osteofibrous dysplasia - contributed by Dr. Mark R. Wick

Keratin immunostain - contributed by Dr. Mark R. Wick

Right distal tibia ankle - contributed by Dr. Mark R. Wick


Various adamantinoma images - contributed by Dr. Mark R. Wick


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