NATURAL HISTORY OF BRANCH-DUCT TYPE INTRADUCTAL PAPILLARY MUCINOUS NEOPLASMS OF THE PANCREAS

Abstract

Background/Aims: Intraductal papillary mucinous neoplasms of the pancreas (IPMNs) consist of two types; branch-duct and main-duct. Branch-duct type is more common and follows a better course than main-duct type, the exact natural history of branch-duct type IPMN has not verified yet. The aim of this study was to investigate the natural course of branch-duct type IPMN. Methods: The medical records of forty five patients with branch-duct type IPMN diagnosed by pancreatogram was reviewed retrospectively. The mean age was 62.9±8.3 years and the mean follow-up duration was 27.4 ±18.9 months. Demographic, clinical and radiologic characteristics were evaluated. The histological findings of resected specimens during the follow-up were also evaluated. Results: Ten patients (22.2%) out of 45 showed enlargement of the cysts during follow-up. Initial size of the cyst in patients with cyst enlargement was smaller than in patients without enlargement in univariate analysis (p < 0.01). The cyst size less than 1.0cm was significantly associated with enlargement of the cyst with odds ratio of 4.48 in multivariate analysis. Ten patients underwent surgical resection and pathology revealed one carcinoma in situ and another invasive adenocarcinoma. The presence of mural nodule was associated with malignant change of IPMNs (p = 0.02). None of unresected cases showed any metastasis or disease-related death. Conclusions: Natural history of branch-duct type IPMNs is generally good. The occurrence of mural nodule but not the speed of size increase was associated with the malignant change of the cyst.