What is anal canal melanoma?

It is different from the more familiar form of Melanoma that begins on sun-exposed skin, although both arise from melanocytes. A lesion inside the anal canal may not be visible externally and may resemble haemorrhoids or another anal condition. Symptoms alone cannot establish the diagnosis.

Anal canal melanoma can present with rectal bleeding, a lump, pain, itching, mucus, altered bowel habits, or a feeling that the bowel has not emptied. Some tumours contain little visible pigment. Diagnosis requires examination and a tissue biopsy; imaging and other tests then help the team determine local extent and whether disease has reached lymph nodes or distant organs. A Sentinel Lymph Node Biopsy may be discussed in selected situations rather than used automatically.

Care is usually planned by specialists in colorectal surgery, oncology, pathology, and radiology. Surgery may range from local Tumour Removal Surgery to a larger operation, depending on the tumour's position, extent, and effect on continence. Immunotherapy or other systemic treatment may be considered according to stage, tumour features, previous care, and general health. Ask the team to explain the aim of each option and its likely effect on bowel function and daily life.

Arrange prompt medical assessment for unexplained rectal bleeding, a new or enlarging anal lump, persistent anal pain, discharge, or a sustained change in bowel habits. Seek urgent care for heavy bleeding, fainting, severe worsening pain, inability to pass stool or gas, or signs of serious illness. These symptoms can have non-cancerous causes, but their persistence or severity warrants examination rather than self-treatment.

Ask where the tumour began, what the biopsy shows, which scans are needed, and whether molecular testing could guide therapy. Request a clear comparison of surgical and systemic options, including recovery, bowel effects, and symptom control. Also clarify the schedule for Follow-Up After Cancer Treatment and whom to contact if new neurological, breathing, abdominal, or bone symptoms develop.