Pleomorphic adenomas is the most common neoplasm of the parotid gland, generally presenting as a slowly growing, firm, well-circumscribed, painless nodule. It is often difficult to separate into benign and malignant categories because its bland histomorphologic and cytologic features. This tumor can be rarely associated with cystic change, hemorrhagic necrosis, or spontaneous infarction. Necrosis of lesional tissue may be associated with malignant transformation, particularly in a pleomorphic adenoma. We report a case of 50-year-old woman presented with a enlarging right parotid mass. Computed tomographic scan demonstrated a right superficial lobe mass with ill-defined border. The preoperative fine needle aspiration yielded necrotic debris and atypical squamous elements that were thought to be compatible with high degree of mucoepidermoid carcinoma. A total parotidectomy with intraoperative frozen section revealed extensive necrosis and diagnosed as malignant tumor. This tumor was finally diagnosed as a pleomorphic adenoma with necrosis on permanent sections. Caution should be exercised in evaluation of the parotid neoplasms with central necrosis to avoid misdiagnosis of such lesions as malignancy.

Pleomorphic adenomas is the most common neoplasm of the parotid gland, generally presenting as a slowly growing, firm, well-circumscribed, painless nodule. It is often difficult to separate into benign and malignant categories because its bland histomorphologic and cytologic features. This tumor can be rarely associated with cystic change, hemorrhagic necrosis, or spontaneous infarction. Necrosis of lesional tissue may be associated with malignant transformation, particularly in a pleomorphic adenoma. We report a case of 50-year-old woman presented with a enlarging right parotid mass. Computed tomographic scan demonstrated a right superficial lobe mass with ill-defined border. The preoperative fine needle aspiration yielded necrotic debris and atypical squamous elements that were thought to be compatible with high degree of mucoepidermoid carcinoma. A total parotidectomy with intraoperative frozen section revealed extensive necrosis and diagnosed as malignant tumor. This tumor was finally diagnosed as a pleomorphic adenoma with necrosis on permanent sections. Caution should be exercised in evaluation of the parotid neoplasms with central necrosis to avoid misdiagnosis of such lesions as malignancy.

parotid gland, pleomorphic adenoma, necrosis, malignancy