June 2018

  • Patient Information
    • 71 year old male presented with a translucent papule on his index finger near the proximal nail fold
  • Clinical Diagnosis
    • Wart
    • Digital mucous cyst
  • Histology

    Sections show acral skin with a central pseudocyst containing mucoid material.

  • Final Diagnosis
    • Digital mucous cysts (DMC) are benign lesions commonly presenting as a solitary, flesh colored papule between the distal interphalangeal joint and proximal nail fold
      • DMC most commonly affect the hands but toes can be involved
      • When arising close to the nail, DMC can cause grooving of the nail plate or partial/complete nail loss
    • Most DMC are asymptomatic but some patients may experience pain, tenderness or decreased range of motion
    • Histopathology reveals acral skin with a psuedocystic space filled with mucinous material and scattered fibroblasts
      • An epithelial lining is not present
    • There are two types of DMC:
      • Some lesions are analogous to ganglion cysts and are related to degenerative changes of the distal interphalangeal joint
      • Other lesions are thought to represent a form of focal mucinosis
    • DMC can resolve spontaneously but most require intervention such as excision, cryotherapy or needling for treament.
  • Summary
    • Digital mucous cysts (DMC) are benign lesions commonly presenting as a solitary, flesh colored papule on the hands between the distal interphalangeal joint and proximal nail fold
    • Histopathology reveals acral skin with a psuedocystic space filled with mucinous material and scattered fibroblasts
    • There are two types of DMC:
      • Some lesions are analogous to ganglion cysts and are related to degenerative changes of the distal interphalangeal joint
      • Other lesions are thought to represent a form of focal mucinosis
    • DMC can resolve spontaneously but most require intervention such as excision, cryotherapy or needling for treament