Radiation-induced oncocytic carcinoma of the parotid in a 66-year-old woman

We report the first case of a radiation-induced oncocytic carcinoma of the parotid. The patient received head and neck radiotherapy as a child and presented approximately 60 years later with a palpable parotid mass. She underwent total parotidectomy with maximum attempt at functional preservation of the key facial nerve branches. Grossly, the parotid mass was a 3.0-cm white firm tumor with a cystic center. On histologic examination, islands of neoplastic cells with oncocyctic features were identified with infiltration of the soft tissues. Mitotic figures were assessed at four per ten high-power fields. Occasional foci of perineural invasion were identified. There was no evidence of lymphovascular invasion. Three periparotid lymph nodes were received; all were negative for malignancy. Final margins were very close (less than 1 mm). The patient received adjuvant radiotherapy to the postoperative bed and ipsilateral high-risk nodal stations. She had an excellent functional outcome and remains without evidence of disease. We discuss the differential diagnosis of radiation-induced tumors of the parotid, as well as the histologic and clinical features of oncocytic carcinomas. We review the literature pertaining to oncocytic carcinoma and its management in the modern era.