Derm

Digital Mucous Cyst

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Digital Mucous Cyst, Focal Mucinosis, Myxoid Cyst, Finger Mucous Cyst

  • See also
  1. Nail Abnormality
  2. Fingernail
  • Epidemiology
  1. Age: Middle aged patients and older (age 50 to 70 years in 80% of cases)
  2. Gender: Twice as common in women
  • Types
  1. Proximal nail fold translucent cysts
    1. Local fibroblast proliferation
    2. Excessive production of hyaluronic acid
    3. No communication with joint space or tendon sheath
  2. Dorsolateral cysts over distal interphalangeal joint
    1. Herniation of joint lining or tendon sheath
    2. Associated with degenerative change of Osteoarthritis
  • Signs
  1. Characteristics
    1. Flesh-colored to translucent Papule or Nodule
    2. Exudes clear viscous fluid when punctured
    3. May become black if lesion Hemorrhages
  2. Involved sites (varies by type of cyst - see above)
    1. Dorsal finger between DIP joint and nail
    2. Often affects second and third fingers
    3. Often located to one side of extensor tendon
  3. Associated findings
    1. Heberden's Nodes at DIP joint (in Osteoarthritis)
    2. Affected finger may have grooved nail
  • Differential Diagnosis
  1. Ganglion Cyst
  2. Gouty Tophi
  • Management
  1. Repeated puncture
    1. Puncture cyst with sterile 25 gauge needle
    2. Express mucous contents of cyst
    3. Repeat procedure on recurrence
    4. May need to be repeated for 5 or more episodes
    5. Cure rate: 70% after repeated punctures
  2. Cryosurgery (Liquid Nitrogen)
    1. Unroof and drain cyst
    2. Apply Liquid Nitrogen in freeze-thaw-freeze fashion
      1. Freezing should include 2 mm margin around cyst
      2. Freeze for 15 to 30 seconds
      3. Allow to thaw for 60 to 90 seconds
      4. Refreeze for 15 to 30 seconds
    3. Cure rate: 85% after single treatment
    4. Complications: Proximal nail fold notching
  3. Aspiration and Local Corticosteroid Injection
    1. Puncture cyst with sterile 21 gauge needle
    2. Inject local Corticosteroid mixture
      1. Lidocaine 1% 0.2 ml
      2. Triamcinolone Acetonide (10 mg/ml) 0.2 ml
    3. High recurrence rate (not recommended)
  4. Simple surgical excision
    1. Digital Nerve Block
    2. Excise cyst and cover with contiguous U-shaped flap
    3. See description in article by Dr. Zuber
    4. Zuber (2001) Am Fam Physician 64(12):1987-90 [PubMed]
      1. http://www.aafp.org/afp/20011215/1987.html
  5. Osteophyte resection by Orthopedics
    1. Indicated for symptomatic cysts refractory to above
  • Course
  1. High rate of recurrence regardless of treatment form
  • References
  1. Habif (1996) Clinical Dermatology, Mosby, p. 778-9
  2. White (1994) Regional Dermatology, Mosby, p. 87
  3. Zuber (2001) Am Fam Physician 64(12):1987-90 [PubMed]