Non-neoplastic or metabolic disease
Hyperostosis cranii ex vacuo

Author: Dariusz Borys, M.D. (see Authors page)

Revised: 3 October 2016, last major update June 2012

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

PubMed Search: Hyperostosis cranii ex vacuo
Cite this page: Hyperostosis cranii ex vacuo. website. Accessed September 24th, 2018.
Definition / general
  • Also called thickened calvarium
  • May be due to intracranial hypotension associated with chronic shunting, as skull lacks the outward pressure needed to expand (Hum Pathol 1994;25:545)
Case reports
Gross description
  • Circumferentially thickened skull, particularly inner table, involvement of calvarium and base
Gross images

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Thickened skull

Microscopic (histologic) description
  • Increased cancellous space with normal trabecular bone
Microscopic (histologic) images

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Figure 2B-increased cancellous space

Differential diagnosis
  • Paget’s disease, fibrous dysplasia, thalassemia, hyperostosis frontalis interna (inner table has varying thickness of lobulated bone)