Skin & Soft Tissue: Epidermoid Cyst
Epidermoid Cyst
Definition
- Also Known as “Epidermal Inclusion Cyst” & “Sebaceous Cyst”
- Benign Keratin Containing Cavity Surrounded by a Cystic Wall of Stratified Squamous Epithelium
- Most Common Skin Cyst
Presentation
- Dermal Nodule
- Skin Colored
- May Have a Central Punctum
- Occur Anywhere Over the Body
- Can Rupture (Cause Inflammation & Pain)
- Can Become Infected (Fluctuant, Erythematous, Painful & Purulent)
Diagnosis
- Mostly Clinical (Based on History and Physical Exam)

Epidermoid Cyst 1

Inflamed Epidermoid Cyst 2
Treatment
- Asymptomatic: Nothing
- Symptomatic or Patient Preference (Cosmesis): Excision
- Failure to Remove Entire Cyst Wall Significantly Increases Risk of Recurrence
- Acutely Inflamed or Infected: Incision & Drainage (I&D)
- Excision Difficult When Inflamed Because Wall is Very Friable

Epidermoid Cyst Excision 3
References
- Peter KD. Wikimedia Commons. (License: CC BY-3.0)
- Fruitsmaak S. Wikimedia Commons. (License: CC BY-SA-3.0)
- SF. Wikimedia Commons. (License: CC BY-SA-3.0)