Keratoacanthoma vs Epidermoid Cyst
How to tell the difference — key features compared side by side.
Feature
Keratoacanthoma
Epidermoid Cyst
Category
Pre-cancerous
Benign
Key feature
Rapidly growing dome-shaped nodule with a central crater. Most dermatologists treat it as low-grade SCC.
Slow-growing, round, skin-colored lump filled with keratin. Benign but can become painfully infected.
Risk factors
Chronic sun exposure; Fair skin; Age over 50
Young to middle-aged adults (most common age group); Male sex (slightly more common); Acne history
Action needed
Any rapidly growing dome-shaped nodule
A cyst that becomes red, painful, swollen, or warm (infection)
Keratoacanthoma
Keratoacanthoma grows from nothing to 1-2cm within 4-8 weeks - a dome-shaped nodule with a central keratin-filled crater giving a volcano-like appearance.
Read full guide →Epidermoid Cyst
Epidermoid cysts are the most common type of skin cyst. They are slow-growing, round, firm, mobile nodules located in the dermis or subcutaneous tissue, filled with keratin (not sebum, despite the common misnomer "sebaceous cyst").
Read full guide →Does yours look more like keratoacanthoma?
Quick self-check
Does this look like keratoacanthoma? Answer 2 questions.
Did it appear rapidly - within weeks?
Does it have a dome shape with a central crater?
Still not sure?
Our full ABCDE checker evaluates 5 clinical criteria dermatologists use.
Full ABCDE check →