What should you know about colon melanoma?

Melanoma is a cancer of pigment-producing cells. When it involves the colon, the disease may be primary in the bowel or may represent spread from melanoma elsewhere, so the clinical history and pathology matter. The phrase should not be used to interpret a bowel symptom by itself.

Possible features can include blood in the stool, a change in bowel habits, abdominal discomfort, fatigue, or unexplained weight change. These symptoms have many possible causes; their presence does not establish melanoma. A specialist may use colon evaluation, biopsy, imaging, and pathology review to define the diagnosis and extent.

If colon melanoma has been suggested, arrange coordinated review with the appropriate gastroenterology, surgery, oncology, and pathology teams. Keep copies of reports and ask whether the lesion is primary or metastatic, whether molecular or pathology details affect decisions, and which areas need staging.

Treatment is individualized. Options may include [Tumour Removal Surgery](/treatments/surgical-oncology/tumour-removal-surgery/), [Immunotherapy](/treatments/systemic-therapy/immunotherapy/), or other care based on the tumour’s location, spread, symptoms, and overall health. [Sentinel Lymph Node Biopsy](/treatments/diagnostics-and-staging/sentinel-lymph-node-biopsy/) is a staging procedure used in selected melanoma settings, not an automatic step for every bowel lesion.

Seek urgent medical care for heavy rectal bleeding, black stools, severe or worsening abdominal pain, persistent vomiting, marked abdominal swelling, fainting, or inability to pass stool or gas. New neurological symptoms such as weakness, confusion, seizures, or a severe headache also need urgent assessment because they can signal serious complications, including [Brain Metastases](/conditions/brain-metastases/).

Ask what the biopsy shows, where the melanoma began, whether scans show spread, and what treatment goal is being pursued. Discuss [Surgical Excision](/treatments/surgical-dermatology/excisional-surgery/), [Skin Cancer Surgery](/treatments/surgical-dermatology/skin-cancer-surgery/), and the plan for [Follow-Up After Cancer Treatment](/treatments/survivorship-and-rehabilitation/post-treatment-surveillance/).