Melanoma lumps under the skin: what to know

Melanoma can present with a firm nodule near a previous skin tumour, along a drainage pathway, or in a nearby lymph-node region. A lump may also be a cyst, lipoma, scar tissue, infection or another non-cancerous change. Its position, growth pattern, firmness, tenderness and relationship to the original melanoma help guide assessment. A clinician may examine the whole skin surface and lymph-node areas and use ultrasound or other imaging before taking a tissue sample.

Contact your melanoma or dermatology team when you notice a new lump, especially if it enlarges or remains present. Record its location and when you first felt it; avoid squeezing or repeatedly pressing it. The clinician may recommend a needle sample, excisional surgery or imaging. A sentinel lymph node biopsy is a separate staging procedure and is not automatically required for every lump. If spread is confirmed, treatment may include surgery, immunotherapy or another approach selected from the full staging picture.

Request prompt review for a growing, hard, fixed or painless lump, a lump near the original melanoma, or swelling in an armpit, groin or neck. Seek urgent help for fever with redness, rapidly increasing swelling, breathing difficulty, severe pain, new weakness, confusion or a seizure. These symptoms need assessment for infection, compression or other urgent problems rather than home observation.

Ask where the lump sits in relation to lymph drainage, whether ultrasound or a biopsy is appropriate, what the sample can show, and how the result would change staging or treatment. Ask how to examine your skin and lymph-node regions between appointments and when follow-up after cancer treatment should occur.