Gastro-gastric intussusception in the setting of a neuroendocrine tumor: A case report.

Background: While in children intussusception is often idiopathic, in adults it is commonly caused by a pathologic condition functioning as a lead point. It is important to note that a variety of pathologic conditions may trigger intussusception, with malignancy being a relatively frequent culprit in adults; this should be considered high on the differential diagnosis during evaluation.

Case Summary: This is a case of a 40-year-old female presenting to the emergency department (ED) with three days of acute on chronic, peri-umbilical abdominal pain described as waxing and waning, and pressure-like in nature. Initial computed tomography (CT) of the abdomen and pelvis with contrast in the ED (after her pain had resolved) re-demonstrated a previously noted 13 mm lesion in the gastric antrum but no clear cause of the pain. Endoscopic ultrasound was pursued, and the mass lesion was sampled fine needle biopsy. Post-procedure the patient experienced another episode of severe pain which prompted a repeat stat CT abdomen and pelvis with contrast; this re-demonstrated the 13 mm antral lesion and in addition was remarkable for a gastro-gastric intussusception. An upper gastrointestinal gastrograffin series was ordered (completed only after the pain had subsided) and showed resolution of the intussusception. Histopathology was consistent with a diagnosis of low-grade neuroendocrine tumor (NET). Surgery was initially deferred during the hospitilization given the low grade pathology of the lesion; however further multidisciplinary discussion between Surgery, Oncology, and Gastroenterology recommended resection given the patient's recurrent abdominal pain with the NET functioning as a lead point for further intussusception, and the patient thus underwent robotically-assisted wedge resection.

Conclusion: We present a unique case of severe, intermittent, peri-umbilical pain related to gastro-gastric intussusception caused by an antral NET lead point. The case highlights the importance of considering neoplasms as the cause of intussusception in adults and the greater diagnostic yield when imaging is obtained while symptoms (in this case severe, episodic abdominal pain) are most apparent.