An apparent primitive mass of the mesentery: A case report.

Introduction: Neuroendocrine tumours (NETs) are rare tumors. 55% of NETs originate in the gastrointestinal tract and the liver is the most common site of distant metastases. Serum chromogranin A is the most common biomarker for assessing the extent of disease and monitoring treatment; carcinoid syndrome occurs in 19% of NETs and is characterized by chronic diarrhea or flushing. Primary mesenteric NETs are rare and have been described only in case reports in literature; our case is an apparent primary mesenteric NETs with a surgical program to remove the mesenteric mass and subrenal interaortocaval and retrocaval lymphadenectomies.

Patient Concerns: A 73-year old man came to us because he had been experiencing abdominal pain for a year and he had recently developed diabetes mellitus. He was an active smoker with arterial hypertension.

Diagnosis: After a computed tomography scan and 68 Gallium-positron emission tomography, a diagnosis of what appeared to be a primary mesenteric NET with retrocaval and interaortocaval lymph nodes was made. Laparoscopic biopsy showed NET G2 positive for serotonin, chromogranin A, synaptophysin.

Interventions: The intraoperative finding of a primitive ileum-NET changed the surgical program. We removed the mesenteric mass with the lymph nodes of the superior mesenteric vessel and the middle distal ileum along with the cecum.

Outcomes: The postoperative course was normal, and the patient was discharged on the seventh postoperative day without signs of short bowel syndrome. Follow-up at 6 months revealed no evidence of short bowel syndrome or disease progression.

Conclusion: 68 Gallium-positron emission tomography does not show NETs smaller than 0.5 mm. Accurate palpation of the intestine is essential during surgery for NETs for two reasons: to find the primitive, and because of the risk of multiple intestinal primitives.