Pathologic observations of intrahepatic peribiliary glands in 1,000 consecutive autopsy livers: IV. Hyperplasia of intramural and extramural glands.

Hyperplastic changes of intrahepatic peribiliary glands have rarely been reported, with the exception of hepatolithiasis. To determine whether there are any hyperplastic changes in the glands in livers without hepatolithiasis, we examined 1,000 consecutive autopsy liver specimens that had no hepatolithiasis. The glands were divided into intramural mucous glands and extramural seromucous glands. The hyperplastic changes were found in "normal" livers and in livers with various hepatobiliary diseases, and they were classified into three categories: hyperplasia of intramural glands (49 cases; 4.9%), hyperplasia of extramural serous acini (35 cases; 3.5%), and hyperplasia of extramural mucous acini (92 cases; 9.2%). Two or more of these three hyperplastic changes occasionally coexisted in the same liver. Hyperplasia of intramural glands was seen rather evenly in normal livers and in livers with various hepatobiliary diseases. Prevalence of hyperplasia of extramural serous acini was high in intrahepatic cholangitis and submassive hepatic necrosis. Prevalence of hyperplasia of extramural mucous acini was high in cirrhosis, submassive hepatic necrosis, cholangitis, systemic infection, and extrahepatic biliary obstruction. The hyperplastic intramural glands and mucous acini of extramural glands contained more neutral, carboxylated, and sulfated mucin than normal glands. Although their pathogenesis is unclear, these hyperplastic changes may enhance seromucous secretion into biliary lumens and may lead to biliary dysfunctions such as retardation of bile flow and increased bile viscosity. These hyperplastic changes may be preexisting conditions predisposing to hepatolithiasis.