Supplementary Material for: Ileocolic Intussusception Secondary to B-Cell Lymphoma: Case report

A 20-year-old man with no relevant medical history presented with right lower quadrant (RLQ) abdominal pain for two months, which had worsened over the preceding three days. Physical examination revealed a tender, palpable mass in the RLQ, while laboratory tests were unremarkable. Abdominal ultrasound demonstrated a characteristic “bowel-within-bowel” appearance, suggestive of intussusception (shown in Fig. 1). Computed tomography confirmed an ileocolic intussusception without an identifiable lead point (shown in Fig. 2).
Colonoscopy revealed a 6-cm ulcerated, subepithelial polypoid lesion arising from the terminal ileum and prolapsing into the cecum, precluding further passage of the scope (shown in Fig. 3). Endoscopic biopsies were inconclusive. The patient improved with conservative management and subsequently underwent an elective laparoscopic ileocolic resection with terminal ileostomy, three weeks later. Histopathological examination confirmed diffuse large B-cell lymphoma (DLBCL) with a high proliferative index (Ki-67 >95%) and negative c-MYC expression.
Staging with 18F-FDG PET/CT demonstrated intense uptake with nodular configuration in the right flank/iliac fossa, corresponding to an apparent intestinal location. No hypermetabolic lymphadenopathy suspicious for metastatic disease is seen in the abdominopelvic region.
The patient completed six cycles of systemic R-CHOP chemotherapy, achieving complete response on post-treatment PET imaging. Ten months after diagnosis, gastrointestinal continuity was successfully restored. He currently remains asymptomatic and in remission, under regular follow-up at the Hemato-Oncology clinic.
Intestinal intussusception is uncommon in adults, accounting for only 1–5% of all bowel obstructions [1]. In contrast to pediatric cases, which are predominantly idiopathic, an underlying cause can be identified in up to 90% of adult cases, with neoplasms accounting for nearly 40% [1,2]. The nonspecific nature of symptoms often delays diagnosis [1,3], making early recognition crucial to prevent complications such as bowel obstruction, ischemia, or necrosis [3].
Primary gastrointestinal lymphoma represents 1–4% of all gastrointestinal malignancies, with approximately 90% being B-cell non-Hodgkin lymphomas (NHL). Among these, DLBCL is the most common subtype and the leading lymphoma associated with intussusception [2]. Imaging plays a central role in diagnosis, whereas surgical intervention is frequently required for both diagnostic confirmation and therapeutic management [3]. Chemotherapy remains a cornerstone of treatment for gastrointestinal NHL [1].