S2821 Ileocolonic Intussusception Associated Large B-Cell Lymphoma

Abstract

INTRODUCTION: Intussusception is characterized by the telescoping of a more proximal portion of the gastrointestinal tract into a more distal portion. This is rare in the adult population, representing 5% of all cases of intussusception. Unlike in children, a pathological lead point is detected in 70–90% of cases, with up to 65% being malignant. Common malignancies leading to intussusception in the small intestine include primary adenocarcinoma, gastrointestinal stromal tumors, carcinoid tumors, and lymphoma. CASE DESCRIPTION/METHODS: A 35-year-old male presented with one month of intermittent right-sided abdominal pain. He reported normal bowel movements and denied nausea or vomiting. On presentation his vitals were unremarkable. Physical examination revealed mild abdominal distention with RLQ tenderness. CT abdomen/pelvis demonstrated RLQ ileocolonic intussusception without obstruction. Initial laboratory values were within normal limits. Colonoscopy revealed a dilated cecum and distal ileum with ileocolonic intussusception, with gross examination concerning for malignancy. Terminal ileal biopsy revealed benign small bowel mucosa with active inflammation. Alpha-fetoprotein was 8.5 ng/mL and carcinoembryonic antigen 0.5 ng/mL .CT chest showed no signs of metastasis. The patient underwent laparoscopic right hemicolectomy with extended small bowel resection. Surgical pathology revealed large B-cell lymphoma of the terminal ileum (positive for CD20, Ki-67) and twenty reactive lymph nodes. Postoperative course was uncomplicated and the patient was discharged home with Hematology/Oncology follow up. DISCUSSION: Intussusception is uncommon in adults, with the ileocolic or ileocecal variety comprising the most rare category. In a review of 14 papers in which 396 intussusception cases were presented, only 83 (20.9%) had ileocolic or ileocecal involvement. Of these, intussusception secondary to malignant causes occurred in 144 (36.4%) cases, with 23 of them resulting from lymphoma. Presentation usually includes non-specific symptoms such as colicky abdominal pain (85%–100%), nausea (41%–75%), vomiting (35%–70%), bleeding (16.4%–27.3%) diarrhea and constipation (22.5%–69%), which play a role in its challenging diagnosis. Considering adult intussusception in patients with recurrent abdominal pain is of critical importance given its high association with malignancy. This case highlights the uncommon diagnosis of adult intussusception caused by large B-cell lymphoma.Figure 1.: CT scan showing RLQ ileocolonic intussusception without obstruction.Figure 2.: Colonoscopy revealed ileocolonic intussusception.