A single-institution experience of neurogenic tumors of the mediastinum.

Abstract

Background Neurogenic tumors of the mediastinum are rare tumors located mainly in the posterior mediastinum. The aim of this study was to report a single-institution experience of these tumors. Methods This study was conducted between 2005 and 2017. Bivariate analysis was performed to assess correlations between the cellularity, mitotic index, presence of a capsule, and potential for malignancy of peripheral nerve sheath tumors. Results There were 86 patients enrolled in the study. The mean age was 42.51 years. Nineteen patients were asymptomatic and their tumors were discovered incidentally. Microscopic diagnosis confirmed a schwannoma in 45 cases, neurofibroma in 12, malignant peripheral nerve sheath tumor in 9, ganglioneuroma in 14, ganglioneuroblastoma in 4, and neuroblastoma in 2. Bivariate analysis showed a significant correlation between the absence of a capsule, the degree of atypia, a high mitotic index, and high cellularity with the potential for malignancy ( p < 0.05). Surgical resection was the main treatment modality in 84 cases. The mean survival was estimated to be 51.309 months. The log-rank test showed a significant difference in survival according to histologic subtype and between benign and malignant tumors ( p < 0.0001). Conclusion Even if radiologic means are helpful in suggesting the diagnosis, a positive diagnosis of neurogenic tumors is based on microscopic features. High mitotic activity and cellularity, and severe cytonuclear atypia are the features most suggestive of malignancy.