Prognosis of minimally invasive carcinoma arising in mucinous cystic neoplasms of the pancreas

While patients with surgically resected non-invasive mucinous cystic neoplasms (MCNs) of the pancreas are cured, the behavior of surgically resected minimally invasive adenocarcinomas arising in MCN has not been well established. We report 16 surgically resected MCNs with minimal invasion defined as unifocal or multifocal microscopic invasive adenocarcinoma confined to the ovarian stroma of the MCN without capsular or pancreatic parenchymal invasion. Pathological findings were correlated with patient demographics, type of surgery, and long-term follow-up. Our study included 15 females and 1 male ranging in age from 25–66 years. The patients were followed for a mean of 48.6 months (range 12–148 months). The MCNs ranged in size from 3.5–25 cm and were all located in the body/tail of the gland. Lymphovascular invasion was not identified in any of the cases and all lymph nodes were negative for tumor. Ten neoplasms had unifocal invasion, while 6 had multifocal invasion. Twelve of the neoplasms were partially submitted for microscopic examination while 4 were submitted entirely. Only one of the 16 minimally invasive MCNs recurred, and that tumor had been minimally sampled pathologically. Our study demonstrates that the majority of patients with minimally invasive adenocarcinoma arising in MCN are cured by surgery, particularly if the neoplasms are completely examined histologically.