Gastrointestinal autonomic nerve (GAN) tumor of the rectum.

Gastrointestinal autonomic nerve (GAN) tumor is a relatively newly defined member of the gastrointestinal stromal tumor family, which is a rare group of mesenchymal neoplasms originating in the bowel wall throughout the entire gastrointestinal tract. A thorough search of the literature revealed only one brief mention of this tumor arising in the rectum. We present a full description of such a tumor and summarize the clinical characteristics, therapeutic measures used, biological behavior, and outcome of this unique case.