Reliability of Clinical Diagnosis of Masses of the Cerebellopontine Angle: A Retrospective Multi-Institutional Study.

Objectives: To assess the accuracy of pre-operative diagnosis of masses of the cerebellopontine angle (CPA) when compared to surgical pathology. Design: Retrospective chart review. Participants: Patients who underwent surgery for CPA masses at two tertiary care institutions from 2007 to 2017. Main outcome measures: Percent concordance between pre-operative and surgical pathologic diagnosis; sensitivity, specificity, positive predictive value, and negative predictive value for predicted diagnoses. Results: Concordance between pre-operative diagnosis and surgical pathology was 93.2% in 411 sampled patients. Concordance was 57.9% for masses other than vestibular schwannoma. Prediction of vestibular schwannoma and meningioma had high positive (0.95 and 0.97, respectively) and negative (0.76 and 0.99, respectively) predictive values. Prediction of facial neuroma had sensitivity of 0.13 and positive predictive value of 0.25. Headache (p = 0.001) and facial weakness (p = 0.003) were significantly associated with different pathologic profiles. Hearing loss was associated with differences in diagnostic prediction (p = 0.02) but not with differences in surgical pathology (p > 0.05). Conclusions: Comparison between pre-operative predicted diagnosis and surgical pathology for cerebellopontine angle masses is presented. Vestibular schwannoma and meningioma were effectively identified while rarer CPA masses including facial neuroma were rarely identified correctly. Clinicians caring for patients with CPA masses should be mindful of diagnostic uncertainty which may lead to changes in treatment plan or prognosis.