Melanoma in situ: lentigo maligna type

Lentigo maligna is a form of melanoma in situ that commonly develops on chronically sun-exposed skin, such as the face, scalp, or neck. It may begin as a flat tan, brown, or black patch and gradually develop uneven colour, an irregular outline, or small darker areas. The patch can be broad and subtle, so its edge may be difficult to distinguish from surrounding sun-damaged skin.

The diagnosis is made from a skin examination and a biopsy reviewed by a pathologist. The report helps show whether the sampled area is in situ and whether the edges contain abnormal cells. A different diagnosis remains possible until tissue has been assessed.

Arrange specialist care so the full visible area and its margins can be assessed. Treatment aims to remove all melanoma in situ while considering the location and the amount of healthy skin that can be preserved. Your clinician may discuss surgical excision or other skin cancer surgery and may recommend further tissue assessment if the edges are involved. Sentinel lymph node biopsy is not routine for every in-situ lesion; its relevance depends on the final findings. Read about Melanoma and Follow-Up After Cancer Treatment for context.

Seek prompt assessment for a flat patch on sun-exposed skin that enlarges, changes shade, develops an uneven border, or contains a new darker focus. After treatment, report a recurring stain at the scar, a new nearby patch, bleeding, or a sore that does not heal. Get urgent wound advice for persistent bleeding, rapidly increasing swelling, fever, or spreading redness after a procedure.

Ask how the diagnosis was confirmed, how far the patch extends, and whether the biopsy margins are clear. Ask which removal method fits the location, whether further tissue sampling is needed, and how the scar and surrounding skin will be monitored. Ask what sun-protection measures are realistic for your daily routine.