Oncocytoma of the Parotid Gland with Facial Nerve Paralysis

Abstract

Parotid gland tumor with facial nerve paralysis is strongly suggestive of a malignant tumor. However, several case reports have documented benign tumors of the parotid gland with facial nerve paralysis. Here, we report a case of oncocytoma of the parotid gland with facial nerve paralysis. A 61-year-old male presented with pain in his right parotid gland. Physical examination demonstrated the presence of a right parotid gland tumor and ipsilateral facial nerve paralysis of House–Brackmann (HB) grade III. Due to the facial nerve paralysis, a malignant tumor of the parotid gland was suspected and right parotidectomy was performed. Oncocytoma was confirmed histopathologically. The facial nerve paralysis was resolved 2 months after surgery. During the follow-up period (one and a half years), no recurrence was observed. As the tumor showed a distinctive dumbbell shape and increased somewhat due to inflammation (i.e., infection), the facial nerve was pinched by the enlarged tumor. Ischemia and strangulation of the nerve were considered to be the cause of the facial nerve paralysis associated with the benign tumor in this case.

Parotid Gland Oncocytoma: A Rare Case and Literature Review

“…Diagnosis by fine-needle aspiration cytology (FNAC) may be very difficult. In fact, we observe oncocytic changes in a large variety of neoplastic and non-neoplastic conditions; otherwise focal sampling of the lesion explains cytology misdiagnosis [1]. It has been reported the sensitivity for the detection of oncocytoma by FNAC is 29% [11].…”

“…The word "oncocyte" was first introduced in 1931 by Hamperl [1]. Oncocytomas are rare tumors that account for 0.1-1.5% of salivary gland tumors and 2.3% of benign epithelial salivary gland neoplasms [1][2][3]. Oncocytomas were first described by Jaffe in 1932 [2].…”

“…Bilateralism is observed in 7% of cases [7]. In the literature, we report a case of facial palsy associated to parotid oncocytoma, which was explained by ischemia and strangulation of the nerve secondary to tumoral inflammation [1]. The newest World Health Organization (WHO) classification describes three entities: nodular oncocytic hyperplasia, oncocytoma, and oncocytic carcinoma [8].…”

“…Oncocytomas are rare tumors and represent less than 1% of all salivary gland tumors [1]. Most oncocytomas arise in the parotid gland.…”

“…Diagnosis is suggested by imaging. Diagnostic confirmation is histological after parotidectomy [1,2].…”