K. Akahoshi1, N. Chiyonobu1, H. Ono1, Y. Mitsunori1, T. Ogura1, K. Ogawa1, D. Ban1, A. Kudo1, M. Tanabe1 1Tokyo Medical And Dental University,Hepato-Biliary-Pancreatic Surgery,Bunkyo-ku, Tokyo, Japan
Introduction:
Intraductal mucinous papillary neoplasms (IPMN) are cystic tumors of the pancreas with the ability to progress to invasive cancer, and being discovered with increasing frequency. Currently, the timing of surgical treatment is determined based on the international consensus guideline. However, pre-operative risk stratification for malignant IPMN is sill difficult. Novel predictors for malignant potential of IPMN are expected to be identified.
Methods:
This is a retrospective, single-center study of IPMN patients who underwent surgical resection between 2005 and 2015, and 81 patients were enrolled. Clinical and pathological data were collected and analyzed. The differences between benign IPMN and malignant IPMN were compared. Malignant IPMN was defined as presence of high-grade dysplasia or invasive cancer based on pathological diagnosis of resected specimen.
Results:
Of the 81 patients, 46 showed benign (low to intermediate dysplasia) and 35 showed malignant IPMN. Malignant IPMN were present in 28% of patients with branch duct type (10/36), 55% with combined duct type (17/31) and 57% with main duct type (8/14). Fifty-nine percent (24/41) of patients with high-risk stigmata and 27% (10/37) with worrisome features exhibited malignant IPMN. High-risk stigmata significantly correlated with malignant potential (p=0.006). Next, cyst growth speed of branch duct type and combined type patients with at least 2 contrast-enhanced imaging studies was measured. Average cyst growth speed of benign IPMN and malignant IPMN patients was 0.979±1.796mm/year and 6.933±2.958mm/year, respectively (p<0.001).
Conclusion:
Rapid cyst growth speed was a predictive factor for malignant IPMN as well as high-risk stigmata. Evaluation of cyst growth speed would contribute to optimize treatment strategy of IPMN patients.