A morphological study of Mucin 1 espression in pleomorphic adenoma of parotid gland

Objectives: To evaluate the immunohistochemical expression of MUC1 in Pleomorphic adenoma (PA) of parotid gland
Methods: A total of 22 cases of pleaomorphic adenoma of parotid glands were retrieved from record files along with their paraffin blocks from the dental departments of all the hospitals in Lahore. Subjects who were receiving or had received treatment (chemotherapy or radiotherapy) and tumors of the salivary glands other than pleomorphic adenoma or multiple tumors of salivary glands were excluded. New histological diagnosis was made on freshly prepared H&E sections followed by application and analysis of immunostains.
Results: Among the positive cases, two third cases were strongly and moderately stained. Cases were divided into two groups; high expression group (++,More than 30% of neoplastic cells stained) and low expression group (-Less than 5%neoplastic cells stained and + More than 5% but less than 30% of neoplastic cells stained) .In tumors with size of less than 3cm , nearly two thid cases were included in low expression group. Less than half of caes were included in high expression group with tumor size more than or equal to 3cm. MUC 1 expression was strongly positive in trabecular subtype of PA.
Conclusions: Expression analysis of MUC1 in pleomorphic adenoma of parotid gland showed that there was an association between the expression of MUC1 and size of the tumor. Increased tumor size of pleomorphic adenoma with strong expression of MUC1 might be helpful to predict the risk of recurrence of the tumor.