Neuroendocrine tumors of the gastrointestinal tract: Case reports and literature review

Figure 1 A 65-year-old female with a history of possible inflammatory bowel disease presented for evaluation of epigastric pain and occasional hematochezia. A: Patient 1, neuroendocrine (carcinoid) tumors as duodenal nodule at endoscopy; B: Solid growth pattern with organoid architecture and bland monotonous cells with lack of significant atypia and increased mitoses. H and E, × 10; C: Neoplastic neuroendocrine cells show diffuse positivity for Chromogranin. Chromogranin, × 20.

Figure 2 A 70-year-old male presenting with epigastric pain and 15 pound weight loss underwent upper endoscopy revealing chronic esophagitis, hiatal hernia, acute and chronic gastritis involving the antrum, and a small polypoid lesion which was found in the duodenal bulb. A: Patient 4, neuroendocrine (carcinoid) tumors as solid spiculated mesenteric mass on computed tomography of abdomen; B: Diffuse infiltration by monotonous bland cells with trabecular growth pattern. Mitoses, atypia and necrosis are not identified. H and E, × 10; C: The tumor cells are diffusely and strongly positive for CD56 immunohistochemical stain. CD56, × 20.

Figure 3 A 40-year-old male with recurrent perianal fistulous disease underwent colonoscopy to rule out inflammatory bowel disease. A: Patient 6, neuroendocrine (carcinoid) tumors as 10 mm ileocecal sessile polyp at colonoscopy; B: Nests of monotonous cells with bland nuclei arranged in organoid pattern. H and E, × 10; C: Carcinoid tumor; Chromogranin A: Marked cytoplasmic positivity.

Figure 4 A 50-year-old female presented for evaluation of gastroesophageal reflux disease and colon cancer screening. A: Patient 7, neuroendocrine (carcinoid) tumors as sessile sigmoid polyp at colonoscopy; B: Organoid growth pattern with regular bland nuclei with indistinct cell borders. H and E, ×10; C: The neuroendocrine cells are positive for Synaptophysin and adjacent colonic glands are negative. Synaptophysin, × 20.