Radiologic, endoscopic, and surgical considerations of melanoma metastatic to the gastrointestinal tract.

Malignant melanoma is the most common malignancy to metastasize to the gastrointestinal tract. In a retrospective computer-assisted data search of over 2500 patients with melanoma registered over the past 10 years, 110 patients have been identified to have premortem gastrointestinal metastatic disease (metastatic disease identified at least 6 months before death). The small intestine (35%), colon (14.5%), and stomach (7%) are the most common sites for metastases. Polypoid or ulcerating masses and intramucosal nodules are typical radiologic presentations for gastric and colonic lesions, while over 50% of the small bowel metastases are polypoid masses that many times act as leading points for intussusception. Endoscopic studies are helpful in the preoperative diagnosis of these lesions. In a subset of 38 patients with symptomatic small bowel metastatic disease, complete resections were performed in 26% of patients, with palliative bypasses being performed in 40%, despite the fact that over 50% of the patients had documented visceral metastasis in other body sites. The operative morbidity rate was 15% with no operative deaths. Ninety percent of patients gained relief of symptoms, and overall survival from the time of confirmed small bowel disease averaged 17.3 months, with a range of 6 months to 9 years. It would seem that patients with melanoma with gastrointestinal metastatic disease can benefit from aggressive radiologic and endoscopic procedures for diagnosis and staging. Only through surgical interventions for symptomatic gastrointestinal disease can the quality of life be improved and life expectancy be extended.