We report on a 25-year-old woman who presented as a teenager with macrocephaly and multiple gastrointestinal lesions including ganglioneuromas, hamartomas, lipomas, juvenile, and hyperplastic polyps in association with extra-intestinal tumors including a retroperitoneal lipoma, storiform collagenoma, and a fibrolipomatous hamartoma. PTEN mutation analysis identified a deletion in exon 2, confirming the diagnosis of Cowden syndrome. While intestinal polyps are common among Cowden patients who undergo endoscopy, and intestinal ganglioneuromas are occasionally reported, they are not usual presenting manifestations. Intestinal ganglioneuromatosis is divided into three subgroups: (1) polypoid ganglioneuromatosis (usually few isolated ganglioneuromas), (2) generalized ganglioneuromatosis (usually associated with NF1 or MEN), and (3) ganglioneuromatous polyposis without known systemic disease, although there are several reported patients with multiple lipomas. This individual with Cowden syndrome closely resembles the latter group, thus we suggest that patients with ganglioneuromatous polyposis, especially in association with lipomas, should be evaluated for possible Cowden syndrome. © 2013 Wiley Periodicals, Inc.