S3047 Intussusception: A Rare Presentation in the Proximal GI Tract

Abstract

INTRODUCTION: Intussusception is a well-documented cause of bowel obstruction in pediatrics but is infrequently encountered in adults, accounting for less than 5% of all cases of intussusception. Typically observed in the small or large bowel, intussusception involving the stomach is rare. We present a unique case of gastro-gastric intussusception due to gastric adenocarcinoma arising in a pyloric gland adenoma with high grade dysplasia, with previous literature demonstrating only 5 other cases in the setting of an adenoma/adenocarcinoma. CASE DESCRIPTION/METHODS: A 57 year-old Caucasian female without significant past medical history presented with intermittent abdominal pain, nausea, vomiting, and weight loss for 3 months. Her labs on admission were notable for hypokalemia and hypomagnesemia, but were otherwise normal. A CT scan showed thickening of the gastric body with concern for gastro-gastric intussusception and underlying neoplasm (Figure 1). The surgical team requested an endoscopy by gastroenterology for biopsy and attempt at reduction, which confirmed the presence of gastric intussusception, beginning at 50 cm with a large, partially circumferential, frond-like mass noted in the gastric body, extending down into the intussusception. Multiple attempts were made to traverse the mass, but were unsuccessful and the pylorus was unable to be visualized nor was the intussusception able to be reduced. Multiple biopsies of the gastric mass were obtained during the procedure, demonstrating hyperplastic polyp tissue with low-grade dysplasia and negative for H. pylori (Figure 2). Two days later, the patient underwent a distal gastrectomy with Roux-en-Y gastrojejunostomy; intraoperative pathology revealed a hyperplastic polyp with high-grade dysplasia. Definitive pathology from the surgical specimen revealed a well-to-moderately differentiated adenocarcinoma arising from a 9 cm foveolar-type gastric adenoma with high-grade dysplasia and metastasis identified in 1 of 19 lymph nodes (Figure 3). DISCUSSION: Intussusception is rarely detected in the proximal GI tract, and when present, is most commonly seen in the setting of a surgical anastomosis, foreign body, or anatomic abnormality. This is the 1st documented case of gastro-gastric intussusception associated with a pyloric type adenoma with high grade dysplasia. Histology on endoscopic biopsies showed dysplasia without malignancy, highlighting that superficial biopsies may be misleading and a high index of suspicion for underlying malignancy should be maintained.Figure 1.: CT A/P with contrast shows thickening of the gastric body with concern for gastro-gastric intussusception and underlying neoplasm, no evidence of gastric obstruction or distant metastasis noted.Figure 2.: Superficial biopsy demonstrating adenomatous epithelium (pyloric gland type).Figure 3.: Invasive front of the tumor with overlying areas of high grade dysplasia.