Merkel cell carcinoma (often mis-typed as “merkel skin cancer”) usually appears as a fast-growing, firm bump on sun‑exposed skin, often pink‑red‑purple or flesh‑colored, and is usually painless. Because it is aggressive and can mimic harmless spots, any new, rapidly enlarging skin bump should be checked promptly by a doctor in person.

What Merkel cell skin cancer looks like

Typical features described by major skin‑cancer organizations include:

  • A firm, raised lump or nodule, often dome‑shaped.
  • Color: flesh‑colored, pink, red, or red‑violet; sometimes purple or the same color as surrounding skin.
  • Usually painless (it often does not itch or hurt).
  • Grows quickly over weeks to a few months.
  • Most often appears on sun‑exposed areas: head, face, neck, and arms, but it can occur anywhere on the body.

Dermatology groups note it can sometimes resemble a stye, cyst, or sore that is growing instead of healing, which is why it is easy to miss without expert review.

One way doctors sometimes summarize it is: “a new, firm, painless, rapidly growing red or skin‑colored bump on sun‑exposed skin in an older adult.”

Important safety note (not a diagnosis)

  • Many harmless lesions (cysts, lipomas, benign moles, insect bites, inflamed follicles) can look similar.
  • No online description or photo can reliably tell you whether a specific spot is Merkel cell carcinoma.
  • The only way to know is with an in‑person exam, and if needed, a skin biopsy by a healthcare professional.

If you have:

  • A new bump that is growing quickly.
  • Any spot that looks different from your usual moles or marks.
  • A “pimple” or “cyst” that does not go away or keeps getting larger.

then you should book a prompt appointment with a dermatologist or primary‑care doctor and show them the spot; tell them it is new and changing so they understand the urgency.

Quick checklist you can use before your visit

This is not for self‑diagnosis, just to describe the spot more clearly to a doctor:

  1. When did you first notice it, and has it changed size, color, or shape since then?
  2. Is it painful, itchy, or bleeding, or is it mostly painless?
  3. Where exactly is it located (face, scalp, neck, arm, leg, trunk)?
  4. Have you had a lot of sun exposure or a weaker immune system (certain medications, transplants, chronic illnesses)?

Write these answers down and take clear photos (with a coin or ruler for scale) to show your clinician; this can help them see how fast it is changing.

Bottom line: Merkel cell skin cancer is rare but aggressive; it tends to be a firm, painless, rapidly growing pink‑to‑violet or skin‑colored bump on sun‑exposed skin, especially in older adults, and anything that fits even part of that description should be evaluated in person as soon as you can.

Information gathered from public forums or data available on the internet and portrayed here.