Outcomes of Radical Resection of Advanced Parotid Malignancies with Temporal Bone Resection: Preliminary Report

Objective: Locally advanced malignancies arising from the parotid gland typically require extended resections that involve temporal bone resection (TBR) and removal of surrounding structures in addition to a parotidectomy for adequate exposure and complete oncologic resection. Several studies have evaluated the outcomes of TBR for advanced lateral skull base malignancies. However, few studies have reported outcomes of TBR for radical resection of parotid malignancies alone. In this study, we review our institution's experience and outcomes in the treatment of advanced parotid malignancies with TBR.

Methods: An IRB approved retrospective chart review of all patients who underwent TBR for the treatment of parotid malignancies at our institution from August 2016 to November 2020 was performed. Twenty-two patients underwent TBR and parotidectomy for the treatment of advanced parotid malignancies with a mean age of 60 years (range: 20–85) of which 18 (82%) were male. Twenty-one patients underwent a lateral TBR and 1 patient underwent a subtotal TBR. Preoperatively, 67% of patients had a cranial nerve VII deficit.

Results: Five salivary duct carcinomas (24%), three acinic cell carcinomas (14%), three adenocarcinomas (14%), and four squamous cell carcinomas (18%) accounted for most tumors encountered. Less frequently, one case of mucoepidermoid carcinoma, adenoid cystic, lymphoepithelial, synovial sarcoma, mammary analog secretory, basaloid, and epithelial- myoepithelial carcinoma was encountered, each in one patient, accounting for 32% (n = 7) of tumors. Twenty-four percent of patients presented with a recurrent tumor for which all had undergone prior treatment with radiotherapy and/or surgery. In addition to TBR and parotidectomy, patients frequently underwent a segmental mandibulectomy (67%), and excision of overlying facial skin (100%), with resection extending to the infratemporal fossa (100%) and jugular foramen (57%). A neck dissection was performed on all patients. CN VII was sacrificed in 19 (86%) patients. Defects were mostly reconstructed with an anterolateral thigh free flap (62%, n = 13). On final pathology, 24% had positive margins and 86%) had perineural invasion. Based on the AJCC 8th edition staging guidelines, 86% of patients had T4 disease and 14% had T3 disease. Nodal disease was present in 67% of patients with extranodal extension present in 71% of them. Fifty-two percent of patients received adjuvant therapy with either radiotherapy (n = 5) or chemoradiotherapy (n = 6). Mean follow-up time was 12 months (range: 1–30). During the study period, 18% (n = 4) developed a recurrence at a median time of 6 months. One was local, the rest were distant. There were two (9%) deaths during the study period, for which the median survival time was 13 months.

Summary: In this preliminary report, we demonstrate that locoregional control of advanced primary and recurrent parotid malignancies is achievable with an extended skull base approach including TBR. Despite its adequate locoregional control, it presents with a high rate of distant metastases. It must be taken into consideration that TBR forms a part of a multidisciplinary management that is essential to optimize outcomes in this population of patients.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
15 February 2022