Arnot Ogden Medical Center elmira, NY, United States
Ami P. Patel, DO, MBA1, Jennifer Jeng, DO2, Michael Kochik, DO2, Erik Raborn, DO, MPH2, Edwin Golikov, DO2, Gary Valvano, DO2, Bruno Mazza, MD3 1Arnot Ogden Medical Center, Corning, NY; 2Arnot Ogden Medical Center, Elmira, NY; 3Arnot Health, Elmira, NY
Introduction: For decades it has been known that patients with inflammatory bowel disease (IBD) are at an increased risk for colorectal cancer, with adenocarcinoma being the most common. Risk of colorectal malignancy increases with years since diagnosis of IBD. However, very rarely diagnosed are mixed adenoneuroendocrine carcinomas (MANEC), comprising of at least 30% adenoma and 30% neuroendocrine components. Less than 20 cases have been reported of a MANEC in ulcerative colitis (UC) patients in the literature. Some hypothesize that chronic colonic mucosal inflammation and distant cytokine release eventually lead to MANECs. We present a case of high grade MANEC diagnosed in the setting of UC.
Case Description/Methods: An 85 year old male with a 4-year history of refractory pan-UC with failure of multiple biologics (TNF alpha inhibitors, monoclonal antibodies), mesalamine, and azathioprine presented with worsening diarrhea, fecal urgency, rectal bleeding, muccorhea, and failure to thrive. He was placed on a long steroid taper. Fecal calprotectin was 1380 μg/g. Colonoscopy revealed severe pan-UC and a 4 cm sessile, exophytic, polypoid lesion in the proximal rectum. Biopsies revealed a high grade large cell neuroendocrine tumor positive for chromogranin, synaptophysin, CDX2, and Ki-67 cellular proliferation index of 40-50%. Robotic subtotal proctocolectomy with end ileostomy was performed with rectal specimen pathology revealing a high grade large cell poorly differentiated neuroendocrine carcinoma with low grade adenocarcinoma, consistent with pT3N1a MANEC. Given a single lymph node was positive, the patient is currently seeking oncologic opinion for potential chemotherapy.
Discussion: The incidence of MANEC in a UC patient is very rare. To our knowledge, there are only 20 cases describing a MANEC diagnosis in a UC patient. There is now discussion as to whether or not MANECs correlate with IBD, specifically UC. In addition, MANEC lesions are associated with poor survival rates due to diagnosis at advanced stages. The decision to proceed with subtotal proctocolectomy for MANEC in an elderly patient with refractory pan-UC without severe co-morbidities was made due to a higher MANEC related mortality rate compared to other causes. Given the aggressive nature of MANECs, further research should be conducted regarding association between MANECs and UC to guide future diagnosis and treatment.
Figure: A 4 cm sessile, exophytic, polypoid lesion in the proximal rectum on colonoscopy status post biopsies revealing a MANEC on pathology.
Disclosures: Ami Patel indicated no relevant financial relationships. Jennifer Jeng indicated no relevant financial relationships. Michael Kochik indicated no relevant financial relationships. Erik Raborn indicated no relevant financial relationships. Edwin Golikov indicated no relevant financial relationships. Gary Valvano indicated no relevant financial relationships. Bruno Mazza indicated no relevant financial relationships.
Ami P. Patel, DO, MBA1, Jennifer Jeng, DO2, Michael Kochik, DO2, Erik Raborn, DO, MPH2, Edwin Golikov, DO2, Gary Valvano, DO2, Bruno Mazza, MD3. P1680 - Coincidence or Not? A Rare Case of a Mixed Adenoneuroendocrine Rectal Tumor in the Setting of Ulcerative Colitis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.
