Rare Case of Isolated Colonic Ganglioneuroma and Review of Literature

Abstract

Isolated colonic Ganglioneuroma is extremely rare and only 16 cases have been reported so far 1 without MEN or colon polyposis syndrome. We are reporting one such case. 51 year old male with history of Hypertension, hyperlipidemia and GERD presented for screening colonoscopy. He denied abdominal pain, hematochezia or unintentional weight loss. He did not have family history of colon cancer. He underwent colonoscopy which revealed sessile polyps in the left colon (Figure 1) which were removed. Biopsy showed ganglioneuromatous polyp. He did not have any clinical evidence of MEN syndrome. Fractionated free plasma metanephrines and 24 hour urine metanephrines were negative which ruled out Pheochromocytoma. There was no evidence of thyroid cancer on imaging. Ganglioneuromas are benign tumors composed of a clonal proliferation of neural crest cells to include nerve fibers, Schwann cells, and ganglion cells. They most commonly arise in the posterior mediastinum and retroperitoneum and less frequently in the intestinal tract. Intestinal ganglioneuromas can occur as part of three different processes including Solitary Polypoid Ganglioneuromas, Ganglioneuromatous Polyposis, and Diffuse Transmural Ganglioneuromatosis. Grossly they appear as small sessile polyps. They are indistinguishable from hyperplastic polyps and adenomas endoscopically. Most of them do not have clinical symptoms and found incidentally. On histologic examination the polyps will display a hypercellular and expanded stroma with cellular proliferation predominantly of spindle shaped Schwann cells with collections of ganglion cells interspersed. The Schwann cells will stain S-100 positive and the ganglion cells will stain with Neuron-Specific Enolase (NSE). If the ganglion cell component difficult to appreciate the diagnosis of neuroma may be considered. Ganglioneuromas have a strong association with Multiple Endocrine Neoplasia (MEN IIB)and to a lesser extent with NF1, Cowden's disease, and Juvenile Polyposis. They have also been found to be associated adenomas and adenocarcinomas. However, in our patient, Ganglioneuroma was isolated. Pathology showed predominantly Schwann cells with ganglion cells (Figure 2) which were positive for S100 (Figure 3) and Neuron Specific Enolase (NSE). In the absence of Diffuse Polyposis Syndrome, diagnosis of Solitary Ganglioneuromatous polyp was rendered.