OBJECTIVETo investigate the clinicopathological features of mucinous adenocarcinoma of salivary glands.

METHODSThe clinical manifestations and histopathological characteristics of 6 cases of mucinous adenocarcinoma of salivary gland were studied by retrospective and routine histopathology and immunohistochemistry.

RESULTSFour mucinous adenocarcinoma occurred in palate and 2 in mouth floor. Average age of patients was 60 years (48 - 70) and males were affected more often than females (4:2). Pathologically, the tumor grew with infiltration of surrounding tissues. The tumor consisted of unitary mucinous cells and mucin pool was obvious. The cell pleomorphism and nuclear mitosis were often seen. Some tumors showed acinus-like structure. Tumor cells often formed incomplete duct-like structure and small clusters floating in mucinous pool. There were intracellular mucin and signet ring cells in the tumor. Tumor cells showed positive reaction to PAS, Alcin blue, and some cytokeratin staining.

CONCLUSIONSMucinous adenocarcinoma of salivary gland is a rare malignant tumor which mainly affects palate and mouth floor of older patients. The tumor may originate from acinic cell of mucous acinus or multi-potential cell of salivary gland.