Colorectal neuroendocrine tumors: A case series

INTRODUCTION: Neuroendocrine tumors (NET) of the colon and sigmoid colon are uncommon compared to colorectal adenocarcinoma. Few reports have been made of NET of the colon and sigmoid colon that presents with peritonitis and large bowel obstruction. CASE PRESENTATION: Here, we report two cases of NET of the colon and sigmoid colon, which were diagnosed and treated at our institution. In our first case, a 66-year-old man with a history of abdominal distension was diagnosed with NET via histopathology of the sigmoid colon. The second case involved a 45-year-old woman with the chief complaints of abdominal distention and inability to defecate; specimen histopathology of the descending colon showed neuroendocrine carcinoma features. Clinical outcome was very poor in our patients: eight months after the resection, the second patient demonstrated a sign of metastasis on the liver. CONCLUSION: An uncommon case of colon and sigmoid colon carcinoma with neuroendocrine and diagnostic difficulties precludes an exact description of the initial diagnostic criteria and management. Thus, our case series offers an overview of initial symptoms, radiological and histopathological features for early diagnosis, and proper management of NET.