Correlation of facial nerve paresis and histopathological type of vestibular schwannoma.

The objective of the study was to evaluate the dependence of facial nerve paresis, as a symptom of cerebellopontine angle tumour, on the histopathological subtype of vestibular schwannoma, diagnosed from a post-operative histopathological examination. We retrospectively analysed 91 surgically treated patients with vestibular schwannoma. We studied the histopathological subtype and the preoperative condition of the facial nerve. The following WHO 2000 subtypes were distinguished: neurinoma cellular (51 cases), neurinoma conventional (23 cases), neurinoma ancient (11 cases), (other types: 2 neurofibroma and 2 ganglioneuroma). We analysed the dependence of facial nerve paresis on the histological subtype of tumours and their sizes. The analysis was based on the traditional classification: Antoni A (11 cases), Antoni B (12 cases) Antoni A/B (23 cases) and Antoni B/A (40 cases). 30 patients (30%) in the analysed group had paresis of the facial nerve preoperatively. Preoperative facial paresis occurred frequently in subtypes "cellular" and Antoni B, and rarely in subtypes conventional and Antoni A and B/A. In the small tumour cases (up to 20 mm), facial nerve paresis occurred frequently in subtypes cellular and conventional, as well as in Antoni A and A/B.