Melanosis peritonei associated with enteric duplication cyst. A case report.

Melanosis peritonei is extremely rare, and only five cases have been reported in the English literature, four in association with ovarian dermoid cysts, and one with a peritoneal cyst. We describe an additional case occurring in a girl two years of age who also had an enteric cyst. This is the first reported case of melanosis peritonei not associated with an ovarian teratoma, but with an enteric duplication cyst. Melanophages were present focally in the submucosa, superficial muscle layer, and ulcer bases of the cyst and extensively as small nodules on the peritoneal surface and in the omentum. The tendency of perivascular nodular aggregation of melanophages favors a hematogenous (or lymphatic) spread rather than implantation. Although clear evidence of melanocytic aggregation is lacking, are speculate that the melanin originated from the esophageal-like squamous mucosa of the cyst.