The long term risk of malignancy in patients with branch duct intraductal papillary mucinous neoplasms of the pancreas

Abstract

In patients (pts) with branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMN), the risk of malignant progression is well described at short- and mid-term. Few data beyond 5 years are available. Patients and methodsProspective study in consecutive patients (pts) with BD-IPMN and follow-up (F/U) ≥60 months to assess long term risk of malignant progression. All computed tomographies and magnetic resonance cholangiopancreatographies performed every 1 or 2 years (depending on the maximum size of cyst) were read by the same radiologist. EUS was performed in case of occurrence of main pancreatic duct (MPD) dilation or mural nodule >5 mm. Size increase was considered significant if >5 mm. Size variation, criteria suggestive of malignancy, operative therapy and pathology were recorded. Results53 pts were included (median age at diagnosis: 61 years, median F/U: 84 months (range: 60–132) including 5 F/U >120 months). Lesions were stable in 38 pts (72%). Size increased in 8 pts (15%) (median increase : 11 (5–33) mm) without mural nodule (MN). One of those was operated on (low-grade dysplasia). A MN appeared in 5 pts (9%). ≥5 mm in 2 pts (5 and 15 mm) who were operated on (intermediate-grade dysplasia in both). The 3 remaining pts (MN < 5 mm) were carefully followed-up. Invasive advanced carcinoma occurred in 2 pts, both after 84 months F/U. In one of these, no imaging changes were noted 12 months before diagnosis of malignancy. ConclusionIn BD-IPMN, the risk of malignant evolution persists after 60 months F/U including invasive carcinomas. F/U imaging surveillance is still necessary beyond this delay in patients fit for potential surgery.