Small bowel tumors: A digestive endoscopy society of Taiwan (DEST) multicenter enteroscopy-based epidemiologic study.

BACKGROUND/PURPOSE: Small bowel (SB) accounts for the majority of gastrointestinal tract but its tumors are rare and always overlooked. In this study, we aimed to evaluate the epidemiology of SB tumors.

METHODS: This multicenter retrospective study utilized endoscopy database from 2006/11 to 2016/07. Baseline demographic characteristics, clinical, radiologic and endoscopic findings were collected.

RESULTS: Totally 103 (34 benign, 69 malignant lesions) patients with SB tumors in 1070 enteroscopic examinations were enrolled. There were male preponderance (56.3% males, 43.7% females), both in benign (52.9%, 49.1%) and malignant (58.0%, 42.0%) lesions, except for subtype gastrointestinal stromal tumors (GISTs) (31.6%, 68.4%). The age (mean ± SD) at diagnosis in malignant SB tumors (62.2 ± 15.6) was older than those with benign tumors (50.7 ± 21.4) (p < 0.01). Bleeding (43.7%), abdominal pain (40.8%) and ileus (10.7%) were the most common clinical presentations. Hamartoma (32.4%) and adenoma (14.7%) were the most common benign histology. Four major malignant histological subtypes were lymphomas (29.0%), GISTs (27.5%), adenocarcinomas (26.1%) and metastatic cancers (14.5%). SB adenocarcinoma patients (>60-year-old, 77.8%) were older than lymphomas (60%) and GISTs (50%). Proximally location rates of lymphomas, GISTs, adenocarcinomas were 25.0% (5/20), 84.2% (16/19), and 88.9% (16/18), respectively.

CONCLUSION: This endoscopy-based study revealed the most common histology of benign SB tumors were hamartoma and adenoma, and malignant ones were lymphomas, GISTs, adenocarcinomas and metastatic cancers. Most of them were male gender, except for GISTs, and with proximal location, except for lymphomas. Further large-scale investigation efforts are warranted to elucidate the epidemiology of SB tumors.