Melanoma in situ explained

The word in situ means in its original place. In this form of melanoma, abnormal cells are limited to the epidermis, the skin's outer layer, and have not been reported as growing into deeper skin on the examined sample. It may look like an uneven brown, black, or mixed-colour patch, although appearance alone cannot determine the diagnosis.

A pathology report helps the care team confirm the diagnosis and whether the sample has clear edges. The clinician may also inspect the rest of the skin and nearby areas for other suspicious marks. The diagnosis is serious, but its meaning is different from melanoma that has invaded deeper tissue.

Treatment commonly focuses on removing the affected skin with a margin chosen for the lesion and its location. Your clinician may discuss surgical excision or another form of skin cancer surgery, followed by examination of the removed tissue. Sentinel lymph node biopsy is not automatically needed for every in-situ diagnosis; ask why it is or is not being considered. Protect the treated area as instructed and attend planned skin checks. Melanoma information can help you prepare for those visits.

Contact your clinician promptly if the site changes, bleeds, becomes sore, or develops a new lump before treatment or during follow-up. After a procedure, seek advice for spreading redness, increasing swelling, fever, persistent bleeding, or wound separation. A new changing mark elsewhere on the skin also needs assessment; it should not be assumed to be related to the original site.

Ask what the pathology report says about the margins, which treatment is recommended, and whether another procedure is needed. Ask how often your skin should be examined, which changes to report, and whether family members should help inspect hard-to-see areas.