When to worry about a new lump or swelling with Merkel cell carcinoma

Merkel cell carcinoma can appear as a firm, painless, or changing skin lump, often on sun-exposed skin. Swelling may also occur in nearby lymph-node areas such as the neck, armpit, or groin. Redness, tenderness, colour change, or rapid enlargement should be described rather than interpreted at home.

A lump can have other causes, including infection, an inflamed cyst, injury, or a treatment effect. Its appearance cannot confirm the diagnosis or show whether disease has spread.

Contact the team managing your skin cancer and give the location, onset, growth, colour, firmness, and any bleeding or discharge. Keep the area clean and avoid picking, cutting, or applying unapproved creams. Bring a list of medicines and mention recent surgery, injections, or skin injury.

An examination may be followed by imaging or a biopsy, depending on the lump’s position and your history. Follow the team’s wound-care instructions if the area has been treated.

Seek urgent care for uncontrolled bleeding, rapidly expanding swelling, severe pain, spreading redness with fever, facial or neck swelling that affects breathing or swallowing, or sudden weakness. These symptoms can signal an urgent problem and need assessment without waiting for a routine visit.

Ask whether the area needs examination today, how to protect it, whether nearby lymph nodes should be checked, which test may be needed, and what changes should be reported immediately. Confirm the after-hours contact route before leaving the clinic.