DIAGNOSTIC AND THERAPEUTIC CHALLENGES IN THE MANAGEMENT OF A CASE OF DEEP LOBE PAROTID GLAND PLEOMORPHIC ADENOMA IN A NIGERIAN TERTIARY HOSPITAL

Abstract

BACKGROUND: Most parotid gland pleomorphic adenomas arise in the superficial lobe of the gland; but about 10-12% arise in the deep lobe, presenting diagnostic and therapeutic challenges.

 OBJECTIVE: To highlight the diagnostic and therapeutic challenges encountered on the way to successful management of a case of a deep lobe parotid gland pleomorphic adenoma.

 CASE REPORT: A 35-year old male who presented with a swelling of 3 years duration in the left parotid region, which was smooth, firm, fairly mobile, and non-tender left infraauricular tumour. Ultrasound scan of the parotid gland revealed a well-defined, oval, slightly hypoechoic mass. Fine needle aspiration cytology diagnosed the lesion as pleomorphic adenoma. Computed tomography (CT) scan showed a well-defined, fairly round, mixed density lesion with some punctate hyperdensities and hypodense areas. The patient was initially booked for superficial parotidectomy by the cervical-transparotid approach but intraoperatively the tumour was found to be well encapsulated within the deep lobe, and elevating the tumour-free superficial lobe. The tumour was completely resected after a very prolonged surgery, sparing the uninvolved part of deep lobe of the parotid gland, the entire superficial lobe, and the facial nerve and all its branches. Post-operative histopathological examination confirmed the diagnosis of pleomorphic adenoma. A review of the patient after 9 weeks showed that his condition has remained surgically, functionally and cosmetically satisfactory.

 CONCLUSION: A very extensive preoperative diagnostic approach is required in the management of pleomorphic adenomas which may uncommonly arise in the deep lobe of the parotid gland. This is especially important to the surgeon to avoid the unforeseen intraoperatively, and help reduce the risk of iatrogenic complications.