Other tumors of bone
Simple bone cyst

Topic Completed: 1 June 2005

Minor changes: 7 May 2020

Copyright: 2003-2019,, Inc.

PubMed search: solitary [title] bone cyst

Nat Pernick, M.D.
Page views in 2019: 7,003
Page views in 2020 to date: 2,455
Cite this page: Pernick N. Simple bone cyst. website. Accessed May 26th, 2020.
Definition / general
  • Also called solitary bone cyst
  • Benign, usually medulla of metaphysis of proximal humerus and femur; also calcaneus
  • Usually males (75%) under 20 years old
  • Presents with advanced lesion, often with pathologic fracture
Radiology description
  • Thin cortex, but without periosteal bone proliferation or expansion of bone
Radiology images

Contributed by Dr. Mark R. Wick

Unicameral bone cyst calcaneus

Unicameral bone cyst, proximal humerus Xray

AFIP images


Radiograph reveals untreated fracture

Unicameral bone cyst

Resected cyst from fibula

Epiphysis of greater trochanter

Prognostic factors
  • Poorer prognosis if cyst near epiphysis
  • Curettage, replace cyst with bone chips
Gross description
  • Cyst with clear yellow fluid lined by brown fibrous membrane
Microscopic (histologic) description
  • Cyst lined by spindle cells and occasional giant cells
  • Connective tissue with prominent vasculature, hemosiderin, cholesterol clefts
  • Surrounding bone may be dense with irregular cement lines
Microscopic (histologic) images

AFIP images

Thin fibrous lining

Osteoid in cyst lining

Curetted material from cyst

Thin fibrous lining membrane

Contributed by Dr. Mark R. Wick

Unicameral bone cyst

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Quiz case

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