Unilateral Multiple Tumorous Lesions of the Parotid Gland

Abstract

Multifocal tumors within the same parotid gland are very rare. We treated 13 patients with multiple tumorous lesions within the unilateral parotid gland. We evaluated the multiple nodules by CT-sialography or magnetic resonance imaging (MRI). These imagings showed clearly two or more distinct nodular-appearing lesions. Recurrent pleomorphic adenoma (6 patients) was predominant, followed by Whartin's tumor (3 patients). The other lesions were two differential parenchymal tumors (polymorphous low grade adenoma/adenoma) within the same gland, a malignant lymphoma, a squamous cell carcinoma metastatic to the gland, and a tuberculous lesion. On palpitation, 9 of the patients had an unilateral tumor, one a palpable parotid mass in the gland, and the other four had two or more tumors in the unilateral gland. The patients with intra-parotid lymph node and metastatic lesions had extra-parotid cervical adenopathy. The clinical features and the differential diagnosis of the unilateral multiple tumorous lesions of the parotid gland are discussed.