Graffeo, Christopher S.

Objectives/HypothesisTo report two patients with a history of microvascular decompression (MVD) for hemifacial spasm who presented with Teflon granulomas (TG) mimicking cerebellopontine angle (CPA) tumors and to perform a systematic review of the English‐language literature.Study DesignCase series at a single tertiary academic referral center and systematic review.MethodsRetrospective chart review with analysis of clinical, radiological, and histopathological findings. Systematic review using PubMed, Embase, MEDLINE, and Web of Science databases.ResultsTwo patients with large skull base TGs mimicking CPA tumors clinically and radiographically were managed at the authors' institution. The first presented 4 years after MVD with asymmetrical sensorineural hearing loss, multiple progressive cranial neuropathies, and brainstem edema due to a growing TG. Reoperation with resection of the granuloma confirmed a foreign‐body reaction consisting of multinucleated giant cells containing intracytoplasmic Teflon particles. The second patient presented 11 years after MVD with asymmetrical sensorineural hearing loss and recurrent hemifacial spasm. No growth was noted over 2 years, and the patient has been managed expectantly. Only one prior case of TG after MVD for hemifacial spasm has been reported in the English literature.ConclusionsTG is a rare complication of MVD for hemifacial spasm. The diagnosis should be suspected in patients presenting with a new‐onset enhancing mass of the CPA after MVD, even when performed decades earlier. A thorough clinical and surgical history is critical toward establishing an accurate diagnosis to guide management and prevent unnecessary morbidity. Surgical intervention is not required unless progressive neurologic complications ensue.Level of Evidence4 Laryngoscope, 127:715–719, 2017

OBJECTIVE Vagus nerve and sympathetic chain cervical schwannomas (VNCSs and SCCSs) are benign nerve sheath tumors that arise in the head and neck. Despite similar presentations that make accurate preoperative diagnosis more difficult, the potential for morbidity following resection is significantly higher for patients with VNCS. Therefore, the authors analyzed a retrospective case series and performed a comparative analysis of the literature to establish diagnostic criteria to facilitate more accurate preoperative diagnoses. METHODS The authors conducted a blinded review of imaging studies from retrospectively collected, operatively confirmed cases of VNCS and SCCS. They also performed a systematic review of published series that reported patient-specific preoperative imaging findings in VNCS or SCCS. RESULTS Nine patients with VNCS and 11 with SCCS were identified. In the study cohort, splaying of the internal carotid artery (ICA) and internal jugular vein (IJV) did not significantly predict the nerve of origin (p = 0.06); however, medial and lateral ICA displacement were significantly associated with VNCS and SCCS, respectively (p = 0.01 and p = 0.003, respectively). Multivariate analysis demonstrated that ICA and IJV splaying with medial ICA displacement carried an 86% probability of VNCS (p = 0.001), while the absence of splaying with lateral ICA displacement carried a 91% probability of SCCS (p = 0.006). The presence of vocal cord symptoms or peripheral enhancement significantly augmented the predictive probability of VNCS, as did Horner's syndrome or homogeneous enhancement for SCCS. A review of the literature produced 25 publications that incorporated a total of 106 patients, including the present series. Splaying of the ICA and IJV was significantly, but not uniquely, associated with VNCS (p < 0.0001); multivariate analysis demonstrated that ICA and IJV splaying with medial ICA displacement carries a 75% probability of VNCS (p < 0.0001), while the absence of such splaying with lateral ICA displacement carries an 87% probability of SCCS (p = 0.0003). CONCLUSIONS ICA and IJV splaying frequently predicts VNCS; however, this finding is also commonly observed in SCCS and, among the 9 cases in the present study, was observed more often than previously reported. When congruent with splaying, medial or lateral ICA displacement significantly enhances the reliability of preoperative predictions, empowering more accurate prognostication.