Ancient Beyond Its Years: Giant Intrathoracic Ancient Schwannoma in an Adolescent

Authors

Abstract

Posterior mediastinal masses in the paediatric population present a diagnostic challenge because the imaging appearances of diverse entities frequently overlap. Neurogenic tumours are among the most common primary neoplasms of the posterior mediastinum, constituting roughly 20% of cases in adults and up to 35% in children. Schwannomas, well-encapsulated tumours arising from the myelin-forming cells of peripheral nerves, represent the commonest benign subtype within this group. The ancient schwannoma is an uncommon variant characterised by protracted degenerative change — cystic transformation, intralesional haemorrhage, vessel wall hyalinisation, dystrophic calcification, and nuclear pleomorphism — that accumulates over years. Despite the alarming histological appearances, ancient schwannoma carries no malignant potential; however, its atypical radiological and microscopic features may prompt an erroneous presumptive diagnosis. We report a 15-year-old girl who presented with a one-year history of progressive exertional dyspnoea and nocturnal dry cough. Contrast-enhanced CT of the chest revealed a large hypodense septated lesion in the right thoracic apex displacing the superior mediastinal vasculature, an appearance that suggested a bronchogenic cyst. She underwent right posterolateral thoracotomy, and a complete en bloc excision of a 7.3 cm encapsulated mass was performed. Histopathological examination confirmed an ancient schwannoma. The postoperative recovery was uncomplicated. This report illustrates the diagnostic pitfalls of an ancient schwannoma in a young patient and affirms the central role of tissue pathology in the evaluation of atypical mediastinal masses.

Keywords:

Schwannoma, mediastinal masses, exertional dyspnea, well-encapsulated tumours

Published

2026/08/22

Issue

Vol. Volume 7-issue 3

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