Duodenal neuroendocrine tumor: A rare case report.

RATIONALE: Duodenal neuroendocrine tumor (d-NET) is a rare tumor originating in the neuroendocrine system. The clinical manifestations of d-NET are similar to those of other digestive tract tumors, resulting in a lack of specificity and complex clinical symptoms. PATIENT CONCERNS: A 55-year-old female patient was admitted to our hospital with a chief complaint of an abdominal mass that had been present for more than 4 months. DIAGNOSES: The upper abdomen enhanced computed tomography scan showed an uneven density mass across the upper abdomen, and the tumor size was approximately 6.2 × 5.8 cm with obvious visible enhancement present in 1 area and a cystic nonenhanced area. The postoperative pathology showed the tumor cells to be positive for chromogranin, synaptophysin, cytokeratin, CD56 (partial weak), negative for vimentin, CD117, DOG-1, CD34, S-100, SMA, desmin, and Ki-67 approximately 2%, which confirmed the diagnosis of d-NETs.
INTERVENTIONS: We preferred laparoscopic surgical exploration, but the tumor started at the ascending part of the duodenum and involved the mesenteric artery. As the branches of the superior mesenteric artery were intertwined with the tumor, it was difficult to operate with the endoscope, so we converted to open laparotomy. The postoperative pathology revealed the presence of d-NET. OUTCOMES: The patient recovered uneventfully and was discharged after the operation. One-month and 3-month follow-up after surgery, showed no evidence of recurrence. LESSONS: Radiological imaging studies are insufficient for the differential diagnosis of abdominal mass from other diseases, whereas surgery is the only radical treatment method, and the preferred surgical method is still active radical resection of the tumor.