Intramucosal adenocarcinoma arising within a colonic polypoid ganglioneuroma in a 21 year old female with Cowden syndrome

Background Cowden syndrome (part of the PTEN Hamartoma Tumor Syndromes) is a relatively rare autosomal dominant genodermatosis which is characterized by the growth of lesions in multiple organ systems, including skin, breast, thyroid, endometrium and central nervous system. While most of these lesions are benign, Cowden syndrome confers a substantial risk for several cancers including breast, thyroid and endometrial cancer. Hamartomas of the colon are seen; while there are reports of colon cancer in patients with Cowden syndrome, specialized screening for colon cancer is typically not recommended (NCCN Practice Guidelines in Oncology, v.l.2009). Here, we report a rare case of a large adenoma with intramucosal adenocarcinoma associated with a colonic ganglioneuroma in a young woman with confirmed Cowden syndrome.