Proteus syndrome: report of intra-abdominal lipomatosis.

Proteus syndrome (PS) is an extremely rare sporadic disorder that manifests as an asymmetric, disproportionate overgrowth of any connective tissues, such as bone, fat, or epidermal nevi, in a mosaic or patchy pattern. This hamartoneoplastic syndrome was first described by Cohen and Hayden. Its prevalence is approximately 1 per 1,000,000 live births, and intra-abdominal expansion has been reported in no more than 20 cases in the literature. The phenotypes of the patients differ because of the variation in the pattern of the overgrowths, making diagnosis difficult. Extremely large subcutaneous lipomas and internal lipomas, which occur rarely, are one of the presentation phenotypes. Here, we present the second patient in the literature with PS involving the epiploon.