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.

Endobronchial ultrasound-guided transbronchial needle aspiration as a diagnostic modality for schwannoma: A case report

“…[ 1 ] Benign schwannoma on CT is characterized by a round or oval hypodense mass with an envelope and well-defined borders, with a uniform to markedly heterogeneous enhancement on contrast. [ 16 ] Margins of the adjacent bone may be sclerosed due to chronic compression. Malignant cases exhibit infiltrative growth with indistinct borders, often with dense heterogeneity within the tumor due to necrosis, hemorrhage, and dystrophic calcification.…”

“…Sometimes, small specimens do not reveal immature components of the tumor, which could lead to a false-negative result. In a study by Mlika et al, [ 16 ] 2 cases of EBUS-TBNA and 3 cases of transthoracic biopsies failed to obtain an accurate diagnosis. However, EBUS-TBNA enabled us to rule out more frequently encountered mediastinal lesions, such as malignant lymph nodes, lymphoma, thymoma, and cysts.…”

“…[22] Although radiological imaging is helpful in diagnosing schwannomas, definitive diagnosis remains based on pathological features. [16] Surgical excision is the preferred treatment for schwannomas. [2,4] Preoperative diagnosis facilitates disease management and prompts further clinical measures.…”

Mediastinal tumors of peripheral nerve origin (so-called neurogenic tumors)

“…The mediastinum can be the site of origin of a variety of benign and malignant tumors of peripheral nerve origin that have been usually reported as “mediastinal neurogenic tumors” (MNT) ( 1 - 4 ). Anatomically, the mediastinum can be compartmentalized into anterior, middle, and posterior regions ( 5 - 12 ), which can be useful in prioritizing differential diagnostic entities when evaluating mass lesions with the assistance of radiologic correlation.…”

“…Anatomically, the mediastinum can be compartmentalized into anterior, middle, and posterior regions ( 5 - 12 ), which can be useful in prioritizing differential diagnostic entities when evaluating mass lesions with the assistance of radiologic correlation. The vast majority of MNT’s arise in the posterior mediastinum, typically arising from the spinal nerve roots, although they may develop from any intrathoracic nerve ( 1 ), such as the vagus nerve, or recurrent laryngeal nerve in the superior mediastinum. The majority of MNT’s occur in adult patients, but pediatric cases are described ( 3 , 4 , 13 ).…”