Primary Paraganglioma of the Facial Canal: An Evidence-Based Approach

Abstract

Objectives To perform an evidence-based review evaluating presenting symptoms, imaging, and management for primary paragangliomas of the facial canal (PPFCs). Data Sources PubMed/MEDLINE, Embase, Cochrane Library, and Web of Science. Review Methods Studies were assessed for quality of evidence and bias with the Cochrane bias tool, GRADE, and MINORS criteria. Demographic data, imaging modalities, management strategies, and status at last follow-up were obtained. Results Sixteen studies met inclusion criteria. In total, 21 patients with PPFCs were identified, 19 of which were histologically confirmed. Most common presenting symptoms included unilateral facial nerve dysfunction (n = 14, 73.7%) and pulsatile tinnitus (n = 8, 42.1%). Mean time from reported onset of facial dysfunction was 17.8 months. Computed tomography findings included an expanded descending facial nerve canal (n = 13, 76.5%). All cases with magnetic resonance imaging reported enhancement with contrast. Of the 18 patients who had surgery, 16 (88.9%) underwent full tumor resection while 1 (5.6%) had partial tumor debulking with adjuvant radiotherapy. Overall improvement in facial weakness was documented in 5 of 9 patients (55.6%) with initial facial nerve dysfunction and >6-month follow-up. No evidence of tumor recurrence was reported. Conclusions PPFCs are extraordinarily rare vascular neoplasms of the temporal bone. Early imaging with both computed tomography and magnetic resonance imaging is essential for narrowing the differential diagnosis, assessing the extent of tumor invasion, and accurate surgical planning. Surgical tumor resection with subsequent facial nerve reconstruction is recommended for patients with facial nerve dysfunction, while tumor biopsy or debulking may be indicated when normal facial movement in present.