Malignant oncocytic tumour of the parotid salivary gland.

A 49-year-old man developed a tumour mass in his right parotid salivary gland nine years after a histologically proven benign mixed tumour of the same salivary gland had been surgically removed. Radical resection of the right parotid salivary gland and associated lymph nodes and soft tissues of the neck was performed. The parotid tumour was composed of oncocytic cells which infiltrated the surviving salivary gland tissue. Most of the excised lymph nodes contained metastatic deposits of oncocytic cells identical to the tumour seen in the parotid. There are no previous reports of the occurrence of both pleomorphic adenoma and malignant oncocytoma in the same salivary gland.