Basal cell adenoma of the parotid gland: a clinicopathological study of nine cases--basal cell adenoma versus pleomorphic adenoma and Warthin's tumor.

The aim of this study is to investigate the clinical and pathological characteristics of basal cell adenoma (BCA) and to compare the diagnosis/treatment of BCA with those of Warthin's tumor (WT) and pleomorphic adenoma (PA). Among 192 patients with benign tumors of the parotid gland who underwent surgery, 9 had BCA. All of these tumors showed a benign pattern on computed tomography and magnetic resonance imaging. The accuracy of fine needle aspiration biopsy (FNAB) for diagnosis of BCA was slightly lower than for PA and WT. Most PA and BCA lesions developed in the upper part of the parotid gland. Considering the gender difference, tumor site, and age, it is necessary to differentiate BCA from PA rather than from WT. There were no significant differences in the duration of surgery, the blood loss, and the incidence of transient facial paralysis between surgical resection of BCA and surgery for PA or WT. BCA is the third most common of the benign parotid tumors, following WT and PA, although its incidence is low. When PA and WT are ruled out by FNAB after a tentative diagnosis of benign tumor has been based on imaging findings, BCA should be considered.