OBJECTIVETo study the relationship of expression of mucin 1 and E-cadherin with recurrence of pleomorphic adenoma in salivary gland, and to investigate the signal to predict the recurrence potential of the tumor.

METHODS; The capsule of tumor was observed by microscope. The expression of mucin 1 and E-cadherin in 33 cases of primary adenoma, 12 cases of recurrent pleomorphic adenomas and 7 cases of malignant pleomorphic adenomas were detected by immunohistochemistry.

RESULTSThere was no significant difference about the status of capsule and the positive rate of mucin 1 expression between primary and recurrent pleomorphic adenoma (P > 0.05). The abnormal distribution of mucin 1 expression was observed in recurrent pleomorphic adenoma (6/8), which was characterized by the positive staining of the whole cytomembrane. On the other hand, positive staining of the primary pleomorphic adenoma was observed on the top of the membrane (19/21). The difference was statistically significant (P < 0.05). The staining pattern in malignant pleomorphic adenoma was similar with the recurrent ones except higher ratio of positive expression. No significant different was observed among the three kind of tumors on the expression rate of E-cadherin (P > 0.05).

CONCLUSIONThe status of capsule didn't have much actual usage in predicting the recurrence of pleomorphic adenoma. There was no significant relationship between the expression of E-cd and the recurrence of the tumor. The abnormal distribution of mucin 1 expression contributes to the invasiveness of the tumor and can be used as the predictive signal for recurrence of pleomorphic adenoma.