PRIMARY MESENTERIC NEUROENDOCRINE TUMOR CAUSING STRANGULATED BOWEL OBSTRUCTION: A RARE CASE REQUIRING EMERGENCY SURGERY happy.hasshi.0423@gmail.com

PE095

PRIMARY MESENTERIC NEUROENDOCRINE TUMOR CAUSING STRANGULATED BOWEL OBSTRUCTION: A RARE CASE REQUIRING EMERGENCY SURGERY

6

Japan

Poster Exhibition only

Primary neuroendocrine tumors (NETs) of the mesentery are exceedingly rare, with only about 30 cases reported in Japan. Their rarity and nonspecific imaging features make preoperative diagnosis challenging. NET should be considered in the differential diagnosis of mesenteric masses to guide appropriate management.

An 86-year-old male was incidentally found to have a mesenteric mass on abdominal CT performed for unrelated reasons. Upper and lower endoscopy showed no abnormalities. Surgery was initially planned but the patient was lost to follow-up. Four years later, he presented with abdominal pain and distension. Contrast-enhanced CT revealed a centrally located mesenteric mass causing strangulated small bowel obstruction. Emergency surgery was performed.

Intraoperatively, the tumor was firmly adherent to the central mesentery, preventing complete resection. Partial tumor removal with segmental small bowel resection was performed. Histopathology confirmed a well-differentiated neuroendocrine tumor (NET G1) arising from the mesentery, with no evidence of other primary lesions. The postoperative course was uneventful; the patient declined adjuvant therapy and remains asymptomatic one year later.

This case highlights the extreme rarity of primary mesenteric NETs and the difficulty of preoperative diagnosis due to nonspecific imaging. Including NET in the differential diagnosis of mesenteric masses is crucial. Early recognition and timely surgical intervention can prevent life-threatening complications such as bowel obstruction. Individualized treatment strategies are especially important for elderly patients who may decline further therapy.