Unilateral multifocal pleomorphic adenoma of parotid gland with panlobular involvement—A diagnostic dilemma

Abstract

A 77-year-old elderly woman of Indian ethnicity presented with complaints of gradual onset progressive increase in size of painless swelling initially noted 8 months back on the right side of face. On physical examination, there was evidence of facial asymmetry with the ovoid swelling being firm in consistency and non-tender measuring 5 6 cm in size. The patient was referred for ultrasonography which demonstrated evidence of a well-defined lobulated hypoechoic lesion measuring 2.6 2.8 cm with central vascularity in the superficial lobe of right parotid. Further, there was a similar hypoechoic lesion measuring 2.7 3.0 cm in the deep lobe (Figure 1). The remainder of the right parotid gland showed increased vascularity which was likely reactive (Figure 2). There was no involvement of ipsilateral submandibular gland and contralateral parotid gland. However, there was significant right level Ib cervical lymphadenopathy. Ultrasound imaging was performed using a Toshiba diagnostic ultrasound system (XarioTM 100, Toshiba Medical Systems Corporation, Tochigi, Japan) with a 5 MHz convex array probe. Pleomorphic adenoma, nerve sheath tumors of the facial nerve, and adenoid cystic carcinoma were considered as differentials. Fine needle aspiration cytology (FNAC) confirmed multifocal pleomorphic adenoma and the patient was referred to general surgery department for further management where she underwent total right parotidectomy.