Merkel Cell Carcinoma vs Epidermoid Cyst

How to tell the difference — key features compared side by side.

Feature
Merkel Cell Carcinoma
Epidermoid Cyst
Category
Malignant
Benign
Key feature
Rare but highly aggressive. Appears as a painless, fast-growing, firm nodule - often flesh-colored or bluish-red.
Slow-growing, round, skin-colored lump filled with keratin. Benign but can become painfully infected.
Risk factors
Age over 50 (median age at diagnosis is 76); Chronic sun exposure on fair skin; Weakened immune system (transplant, HIV, chronic lymphocytic leukemia)
Young to middle-aged adults (most common age group); Male sex (slightly more common); Acne history
Action needed
A rapidly growing, painless, firm nodule on sun-exposed skin
A cyst that becomes red, painful, swollen, or warm (infection)

Merkel Cell Carcinoma

Merkel cell carcinoma is a rare and aggressive neuroendocrine skin cancer that develops in Merkel cells, which are sensory cells located near nerve endings in the skin. It is approximately 40 times rarer than melanoma but has a higher mortality rate stage-for-stage.

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 merkel cell carcinoma?

Quick self-check

Does this look like merkel cell carcinoma? Answer 2 questions.

Is the nodule firm, dome-shaped, and painless?

Has it grown rapidly (weeks rather than months)?

Still not sure?

Our full ABCDE checker evaluates 5 clinical criteria dermatologists use.

Full ABCDE check →