Malignant Neoplasms in Otology

Abstract

Temporal bone malignancies are reported to have an incidence of 6 in 1 million individuals. Histologically, squamous cell carcinoma accounts for 60% of the cases followed by basal cell carcinoma and adenoid cystic carcinoma. Aetiological factors include ultraviolet radiation, external beam radiation, history of long-standing chronic otitis media, immunosuppression and human papillomavirus. Clinical presentation overlaps with other inflammatory conditions of the temporal bone. Warning signs to suspect malignancy are facial nerve weakness, persistent pain, lymphadenopathy, trismus and lower cranial nerve weakness. Temporal bone malignancies are unique in that there is no AJCC/UICC TNM staging. The preferred staging system is the University of Pittsburgh system. Surgery is the main treatment modality with lateral temporal bone resection being the minimum oncologically safe procedure. Once disease extends towards middle ear and mastoid, subtotal temporal bone resection should be undertaken. Indications for adjuvant radiotherapy include T2 or greater tumours, lymphadenopathy, positive margin, perineural invasion and recurrent tumours. Tumours that are inoperable due to petrous apex, cavernous sinus and internal carotid artery encasement should be considered for various non-surgical treatment modalities as detailed in the chapter. Adjunctive procedures like parotidectomy and condylectomy should be tailored to the radiological extent.