A Case of Giant Pleomorphic Adenoma of the Parotid Gland with Multiple Distant Metastases

Abstract

Pleomorphic adenomas are the most common type of all benign salivary gland tumors. Sometimes, they grow over long periods of time to reach giant sizes.

We report a case of giant pleomorphic adenoma of the right parotid gland. A 52-year-old man presented to us with a 6-year history of a gradually enlarging parotid gland tumor, which had begun to grow more rapidly during the previous year. Initial examination revealed a giant tumor of the right parotid gland without facial palsy. We suspected pleomorphic adenoma and removed the giant tumor. The tumor was 30×21×16 cm in size and the resected tumor weight was 6080 g. Histopathological examination revealed the diagnosis of pleomorphic adenoma, with no evidence of malignancy.

At 1 year 6 months after the surgery, a mass was observed in the right neck. CT revealed metastatic lesions in the cervical lymph node, lungs, rib, liver and kidney. The patient received chemotherapy (CBDCA+PTX), despite which tumor progression was observed. The patient died of respiratory failure due to lung metastases at 3 years after his first visit to our hospital.

In patients with pleomorphic adenoma, the possibility of malignant transformation, local recurrence, and distant metastasis should be borne in mind and patients should be followed up closely.