Evaluating the diagnostic value of double-balloon enteroscopy combined with endoscopic ultrasonography for primary small intestinal lymphoma.

Background: Primary small intestinal lymphoma (PSIL) is a rare malignancy with heterogeneous clinical and pathological features, making accurate diagnosis challenging. Objectives: To investigate the clinical value of double-balloon enteroscopy (DBE) combined with endoscopic ultrasonography (EUS) in the diagnosis of small intestinal lymphoma. Design: Retrospective cohort study. Methods: We retrospectively reviewed 21 patients with pathologically confirmed PSIL who underwent both DBE and EUS at the Department of Small Intestinal Endoscopy, The Sixth Affiliated Hospital of Sun Yat-sen University, between September 2022 and May 2025. Clinical data were collected and analyzed in combination with pathological findings. Results: A total of 21 patients were included (12 males, 9 females; median age of 52 years, range 31-87 years. Subtypes of B-cell lymphomas included diffuse large B-cell lymphoma (n = 5), follicular lymphoma (n = 3), and mucosa-associated lymphoid tissue lymphoma (n = 6). T-cell lymphomas included peripheral T-cell lymphoma (n = 7). Endoscopic findings were classified into five categories (1): hypertrophic type (2), exophytic tumor type (3), follicular/polypoid type (4), ulcerative type, and (5) diffusion type. EUS classification included superficial spreading (38.1%, 8/21), diffuse infiltrative (42.9%, 9/21), and nodular (19.0%, 4/21). Conclusion: DBE combined with EUS provides complementary morphological and structural information for the diagnosis of PSIL, improving clinical recognition and subtype characterization. Future multicenter studies with larger cohorts are warranted to validate these findings and establish standardized diagnostic protocols.