Clinicopathological features and prognosis of mucin-producing bile duct tumor and mucinous cystic tumor of the liver: a multi-institutional study by the Japan Biliary Association.
BACKGROUND
The aim of this study was to determine the clinicopathological features and surgical outcomes of mucinous cystic neoplasm of the liver (MCN) and mucin-producing intraductal papillary neoplasm of the intrahepatic bile duct (M-IPNB).


METHODS
We performed a multi-institutional, retrospective study of patients with MCN or M-IPNB pathologically defined by the presence or absence of an ovarian-like stroma.


RESULTS
The M-IPNB and MCN were diagnosed in 119 and nine patients, respectively. MCN was observed in female patients, while M-IPNB produced symptoms of cholangitis. M-IPNBs were classed as low or intermediate grade in 53 cases, high grade in 23 and invasive carcinoma in 43. Fifty-one of the M-IPNBs were the pancreatobiliary type (PT), 33 were the intestinal type (IT), 23 were the oncocytic type (OT), and 12 were the gastric type (GT). The 1-, 5- and 10-year survival rates for the 105 patients with M-IPNB were 96%, 84% and 81%, respectively, while the 5-year survival rate for patients with MCN was 100%. OT and GT M-IPNB had better 10-year survival rates than PT and IT M-IPNB.


CONCLUSIONS
Although MCN has different features from M-IPNB, both diseases have a good prognosis after resection. The cellular type of M-IPNB appears to predict outcome.