Melanoma metastatic to the colon: case series and review of the literature with outcome analysis.

PURPOSE

Symptomatic melanoma of the colon is rare. The aim of this study was to determine the incidence, presenting signs and symptoms, and survival correlation.

METHODS

A retrospective review was performed of all patients treated in Mayo Clinic facilities from 1960 to 2000 for primary and metastatic melanoma. We identified 24 patients with metastatic melanoma to the colon.

RESULTS

There were 24 patients (14 males) with an average age of 60.4 years at the time of metastatic involvement. The interval time between diagnosis of the primary and metastatic disease to the colon was 7.47 years. The most common presentation was bleeding. Colonoscopy was used in 11 patients and diagnostic in 9. Eighteen patients underwent resection, and seven patients had positive nodes. The average time until death after operation was 27.5 months (range, 30 days to 65 months). Nonoperative candidates died within 7.8 months after diagnosis. One-year and five-year survival for resected patients were 37 and 21 percent, respectively. Patients with negative nodes had an average survival time of 34.7 months compared with 20.4 months in patients with positive nodes. Perforation and bowel obstruction directly correlated with poor survival, with an average life expectancy of ten months (P = 0.03).

CONCLUSIONS

Metastatic melanoma of the colon is rare. Segmental resection is justified and can be successfully completed in 95 percent of patients who undergo attempted resection. Survival of less than ten months is most accurately predicted by signs and symptoms of obstruction or perforation at presentation (P = 0.03).