eP310 - Multifocal Neuroendocrine Tumor Found During Proctectomy for Hirschsprung’s Disease: A Case Report

Purpose/Background: Multifocal neuroendocrine tumors (NET) are rare in the young. We present the case of a 23-year-old male with delayed diagnosis of Hirschsprung's disease with previous colectomy and end-ileostomy, who was found to have multifocal NET in the rectum during evaluation ostomy reversal. In our case report, we describe the history and presentation of a complex patient with unknown Hirschsprung's disease with multiple previous abdominal surgeries as a pediatric patient, newly found to have multifocal NET.Methods/Interventions: We describe a 23-year-old male with previous history of total abdominal colectomy at 2 months of age due to toxic megacolon due to C. difficile colitis. He required an end ileostomy during his index operation. An ostomy takedown was attempted without further workup at 10 years of age which was complicated by an anastomotic leak and return to ileostomy. He then underwent workup for Crohn’s disease given family history, however no granulomas were found on his pathology. Several years later, he was evaluated for ostomy takedown again. On review of his chart, it was noted he had meconium plug as an infant as well as history above. Due to this, a full thickness rectal biopsy was undertaken which revealed aganglionosis as well as an incidental 1mm neuroendocrine tumor. Review of previous colonic pathology revealed hypoganglionosis of the distal colon supporting the diagnosis of Hirschsprung’s. Proximal rectal biopsy was performed at time of exploratory laparotomy and frozen section demonstrated aganglionosis with hypertrophic nerves. Therefore, completion proctectomy with IPAA and DLI was performed.Results/Outcomes: On his full thickness rectal biopsy, no ganglion cells were identified with calretinin stain negative for intramucosal nerve fibers. There was an incidental finding of well-differentiated neuroendocrine tumor, confirmed with chromogranin and synaptophysin stains (figures 1 and 3). The new finding of aganglionosis was in direct contradiction to a suction rectal biopsy performed as an infant which was thought to have ganglion cells, but also noted to have "nerve twigs" which may have been hypertrophic nerve bundles. The original paraffin block was unobtainable for reexamination as it has likely been exhausted. On final pathology of completion proctectomy, multifocal nets were identified. All were subcentimeter without extension.Conclusion/

Discussion: After literature review, we believe this may be the first recorded patient with a delayed diagnosis of Hirschsprung’s disease later found to have a well-differentiated neuroendocrine tumor in the diverted rectum. Well-differentiated neuroendocrine tumors (carcinoid) are often found incidentally and in the setting of chronic inflammatory disease. They are also associated with ret mutations as is Hirschsprung’s disease. Given this patient’s complex surgical history and extensive pathologic assessments, the scenario provides a unique presentation of both delayed diagnosis of Hirschsprung’s disease and incidental identification of multifocal neuroendocrine tumor in a diverted aganglionic segment."Chromogranin staining of rectal frozen biopsy

Focal intramucosal well-differentiated neuroendocrine tumor (carcinoid), confirmed with chromogranin and synaptophysin stains
Hematoxylin and eosin stain of rectal frozen biopsy

HE stain confirming no obvious presence of ganglion cells in the rectal specimen.
Synaptophysin staining of rectal frozen biopsy

Focal intramucosal well-differentiated neuroendocrine tumor (carcinoid), confirmed with chromogranin and synaptophysin stains"