Other tumors of bone
Solitary bone cyst

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

Revised: 16 August 2018, last major update June 2005

Copyright: (c) 2003-2018,, Inc.

PubMed search: solitary [title] bone cyst

Cite this page: Pernick, N. Solitary bone cyst. website. Accessed December 15th, 2018.
Definition / general
  • Also called simple 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

Images hosted on PathOut server:

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

Images hosted on PathOut server:

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

Images hosted on other servers:

Quiz case

Wall of cyst