Objective: To investigate the clinicopathological character of polymorphous low-grade adenocarcinoma (PLGA) and reasons of its misdiagnosis.

Methods: Nine cases ultimately diagnosed as PLGA in recent years were retrieved from the files of the Affiliated Stomatological Hospital of Nanchang University. Clinical and pathological features were reviewed.

Results: Seven cases occurred on palate glands and two cases on parotid glands; of the nine cases, only one was diagnosed as PLGA preoperatically, while others were misdiagnosed preoperatically and during operation (fine needle aspiration cytology or frozen section). Three cases were diagnosed as pleomorphic adenoma, three as mucoepidermoid carcinoma, one as cystic adenoid carcinoma, one as Warthin’s tumor. Ultimate diagnosis was based on immunohistochemistry examination which showed that CK, SMA, UEA and histaminase D were positively expressed in the tumor.

Conclusion: PLGA arises often in the palate minor salivary glands or tail part of parotid glands. Differential diagnosis should be made because it is easily be misdiagnosed as other tumors.

Conflict of interest: None declared.