Endoscopic and histopathologic features of gastrointestinal polyps in Cowden's disease

Cowden's disease (CD) is a genodermatosis, characterized by autosomal dominant transmission, a high prevalence of breast and thyroid malignancies and the association with gastrointestinal (GI) polyps. There are few systematic studies of this disease and the distribution and histopathology of GI polyps have not been determined rigorously. Therefore, as part of a multidisciplinary evaluation, we studied in detail the occurrence, distribution and histology of polyps in four patients (2 M, 2 F; mean age: 45.5 yrs, [range: 41-52]) from two unrelated kindreds. Three patients had typical skin manifestations, thyroid and/or breast abnormalities as part of CD. The upper and lower GI tract were thoroughly inspected by video endoscopy and representative biopsies were obtained for histologic evaluation. All patients were found to have GI polyps. None were found in the esophagus, but 3/4 patients had 14, 4 and 55 gastric and/or duodenal polyps, respectively, ranging in size from 2-5mm. All but one biopsy revealed hamartomas with smooth muscle proliferation and the majority (77%) occurred in the antrum. One biopsy of a 2 mm duodenal polyp showed a benign lymphoid follicle. All patients had nonadenomatous colonic polyps ranging in number from 3-57 (3, 6, 31, 57) with a size not exceeding 6 mm. Almost all (86%) were distributed in the left colon and rectum. Except for one inflammatory cecal polyp and one hyperplastic sigmoid polyp all other colonic biopsies revealed hamartomas with lipomatous or smooth muscle proliferative or ganglioneuromatous components. No adenomatous polyps or colon cancer were detected. The endoscopic and histopathologic findings strengthened the diagnosis of CD in 3 patients, but in one patient minimal GI tract involvement might represent a variably low expressivity of CD. We conclude that multiple GI hamartomas are a common feature of CD predominantly found in the antrum and the left colon. Therefore, in patients with suspected CD or a family history of CD, endoscopic screening of both the upper and lower GI tract should be performed. Vice versa, in patients with multiple hamartomas on endoscopic exam the diagnosis of CD should be considered, particularly because of the possibility of development of breast and thyroid malignancies in these individuals.