Branch-duct intraductal papillary mucinous neoplasms: Observations in 145 patients who underwent resection

Background & Aims: Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas arising in branch ducts are thought to be less aggressive than their main-duct counterparts, and guidelines for their conservative management were recently proposed. This study describes the combined experience of 2 tertiary centers with branch-duct IPMNs aiming to validate these recommendations. Methods: A review of 145 patients with resected, pathologically confirmed, branch-duct IPMNs between 1996 and 2005 was conducted. Results: Sixty-six patients (45.5%) had adenoma, 47 (32%) borderline tumors, 16 (11%) carcinoma in situ, and 16 (11%) invasive carcinoma. Median age was similar between benign and malignant subgroups (66 vs 67.5 years, respectively). jaundice was more frequent in patients with cancer (12.5% vs 1.8%, respectively, P =.022) and abdominal pain in patients with benign tumors (45% vs 25%, respectively, P =.025). Forty percent of tumors were discovered incidentally. Findings associated with malignancy were the presence of a thick wall (P <.001), nodules (P <.001), and tumor diameter >= 30 mm (P <.001). All neoplasms with cancer were larger than 30 mm in size or had nodules or caused symptoms. After a mean follow-up of 45 months, the 5-year disease-specific survival for branch-duct IPMNs with noninvasive neoplasms was 100% and, for invasive cancer, was 63%. Conclusions: This large cohort of resected branch-duct IPMNs shows that cancer is present in 22% of cases and validates the recent guidelines that indicate absence of malignancy in tumors < 30 mm, without symptoms or mural nodules.