What is the treatment for an epidermal cyst?

Management of Epidermoid Cysts

Epidermoid cysts are benign, encapsulated subepidermal nodules filled with keratin material that require complete surgical excision with removal of the entire cyst wall for definitive treatment and to prevent recurrence. 1

What is an Epidermoid Cyst?

Epidermoid cysts (also known as sebaceous cysts) are:

• Benign encapsulated subepidermal nodules
• Filled with keratin material
• Commonly found on areas with hair follicles
• Usually present with an epidermal punctum (a clinical diagnostic hallmark)
• Can vary in size from small to several centimeters in diameter

Treatment Approach

For Non-Inflamed Epidermoid Cysts:

1. Complete surgical excision is the treatment of choice 1, 2
   • Requires removal of the entire cyst wall to prevent recurrence
   • A minimum 4-mm margin around the cyst border is recommended 1
   • Can typically be performed under local anesthesia 2
   • Low complication rate of approximately 2.2% 2

For Inflamed Epidermoid Cysts:

1. Incision and drainage is the recommended first-line treatment 1
   • May need to postpone complete excision until inflammation subsides 3

Surgical Techniques:

1. Standard excision:

   • Elliptical incision over the cyst
   • Careful dissection around the cyst wall
   • Removal of the entire cyst intact
   • Closure with sutures 1

2. Minimal incision technique:

   • 2-3 mm incision
   • Expression of cyst contents through compression
   • Extraction of the cyst wall through the small incision
   • Does not require suture closure
   • Particularly useful for cosmetically sensitive areas 3

3. Negative-pressure suction technique:

   • Useful for large cysts (>2 cm)
   • Uses suction instead of lateral pressure
   • Allows complete removal through a small incision
   • Reduces risk of cyst rupture 4

Post-Operative Care

• Keep the surgical site covered with a dry dressing
• Keep the wound clean and dry
• Monitor for signs of infection
• Schedule follow-up to assess wound healing and remove sutures (typically within 7-14 days) 1

Antibiotic Considerations

• Antibiotics are generally not necessary unless there are signs of systemic infection
• Consider antibiotics only if the patient has:
  • Systemic inflammatory response syndrome (SIRS)
  • Temperature >38°C or <36°C
  • Tachypnea >24 breaths/min
  • Tachycardia >90 beats/min
  • WBC >12,000 or <400 cells/µL
  • Markedly impaired host defenses 1

Pathological Examination

Submit excised tissue for pathological examination if:

• Cyst size is >1.5 cm
• Suspicious features are present (nodular mass, ulceration, extensive scarring, rapid growth)
• Unusual clinical presentation
• To rule out potential malignancy 1

Complications and Outcomes

• Recurrence rates range from 2.2-8.3% depending on the technique used 1, 2
• Main cause of recurrence is incomplete removal of the cyst wall 1, 5
• Infection is the most common complication, occurring as a reaction to rupture of the cyst wall 1

Special Considerations

• For multiple cysts, each one requires individual treatment 5
• Giant epidermoid cysts (>5 cm) may require more extensive surgical planning 6
• Rare genetic disorders with multiple cysts include Gardner and Lowe syndrome 2

Common Pitfalls to Avoid

1. Incomplete removal of cyst wall: Ensures high recurrence rates
2. Attempting excision during active inflammation: Makes complete removal difficult and increases complication risk
3. Failure to recognize suspicious features: Could miss malignant transformation
4. Excessive lateral pressure during removal: May cause unintended rupture or fragmentation of the cyst wall