Learning Radiology xray montage

Epidermal Inclusion Cyst
Epidermoid Cyst of Bone

General Considerations


  • Associated with trauma, especially penetrating trauma
  • Usually in bones that are superficially located such as fingers, foot and calvarium
  • Implantation of epithelium that form cysts leading to bone erosion
  • Subungual crush-type injuries have been associated with inclusion cysts as has prior surgery

Clinical Findings

  • May develop with in weeks or years of fingertip injury
  • Pain at site of lesion
  • Mass

Imaging Findings

  • Frequently seen in terminal phalanx
  • Solitary, lytic lesion
  • May be expansile
  • May have a thin sclerotic border

Differential Diagnosis

  • Enchondroma
  • Metastases (rare)
  • Glomus tumor


  • Surgical curettage


  • May recur if incompletely curetted


  • Excellent 

Epidermal Inclusion Cyst

Epidermal Inclusion Cyst

Epidermal Inclusion Cyst. White arrows pint to an expansile lytic lesion in the terminal phalanx
of the index finger in a characteristic location for an epidermal inclusion cyst of the hand.

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