S2143 The Gang's All Here: A Rare Case of Polypoid Ganglioneuroma of the Colon

Abstract

Introduction: Ganglioneuromas are rare benign growths characterized by proliferation of nerve ganglion cells, nerve fibers & supporting cells of the nervous system. These growths have mostly been described in children but occur in adults as well. They are usually found in the mediastinum, retroperitoneum and adrenal glands but rarely, they occur in the gastrointestinal tract. Clinical manifestations depend on the location and size but can include abdominal pain, constipation, bleeding or obstruction. There are no known modifiable risk factors, but in some cases, they are associated with rare genetic syndromes like Cowden, Juvenile Polyposis and Peutz-Jeghers. Herein, we report a rare case of an isolated cecal ganglioneuroma. Case Description/Methods: Our patient was a 63-year-old female with no pertinent past medical history who presented for a routine screening colonoscopy. She had normal vital signs and no abnormal laboratory findings. During the colonoscopy, cold forceps polypectomy was performed to retrieve 2 3-mm polyps in the ascending colon and one 2 mm polyp from the cecum. Hematoxylin and eosin staining of the cecal polyp revealed evidence of spindle cell proliferation accompanied by large cells with prominent nucleoli, consistent with ganglion cells. The immunostaining of the cecal polyp was reactive for the S100 protein but was negative for markers of stromal tissue (CD34, CD117, smooth muscle actin, desmin, epithelial membrane antigen). The concurrence of these findings was consistent with a diagnosis of polypoid ganglioneuroma (Table). Discussion: Colonic ganglioneuromas are divided into 3 major groups: polypoid ganglioneuromas, ganglioneuromatous polyposis & diffuse ganglioneuromatosis. Most of these tumors are found incidentally on screening colonoscopy. Though most of these tumors are benign, few reports have noted an associated incidence of colorectal cancer. Genetic testing is advised if there is existence of a genetic syndrome. There is a lack of guidelines regarding best practice management of these tumors as well as lack of consensus regarding screening measures & follow up surveillance colonoscopy for recurrence. However, similar to other cases reported in the literature that have been successfully treated with polypectomy, the tumor in our case was excised safely endoscopically. Thus endoscopic resection can be a curative method for solitary ganglioneuromas. We believe that awareness & proper counseling will translate into better care of patients with such tumors. Table 1. - Classification of colonic ganglioneuromas with identifying features 1. Polypoid ganglioneuroma - small (< 2cm) & solitary- sessile or pedunculated 2. Ganglioneuromatous polyposis - numerous (often 20-40)- sessile or pedunculated 3. Diffuse ganglioneuromatosis - can range from 1-17 cm in size- present as disseminated, nodular, intramural or transmural lesions