BACKGROUND
Posterior mediastinal schwannomas are relatively uncommon. Cases presenting with abdominal pain as the initial symptom—particularly those involving massive benign tumors that occupy nearly the entire thoracic cavity, resulting in complete collapse of the ipsilateral lung and mediastinal shift—are exceedingly rare.
CASE REPORT
A 48-year-old woman presented with a dull epigastric pain. Initial contrast-enhanced chest computed tomography (CT) on admission revealed a mass occupying nearly the entire left thoracic cavity, which resulted in complete left lung collapse and mediastinal shift. Subsequent contrast-enhanced CT, chest magnetic resonance imaging (MRI), and percutaneous needle biopsy confirmed the diagnosis of a posterior mediastinal schwannoma. The patient underwent surgical resection and had an uneventful postoperative recovery, with satisfactory re-expansion of the left lung.
CONCLUSIONS
For large posterior mediastinal tumors—particularly those causing pulmonary compression and mediastinal shift—preoperative integration of contrast-enhanced CT, functional MRI, and nerve root assessment is essential to delineate tumor vascularity and its relationship with intervertebral foramen nerve roots. For intrathoracic masses amenable to biopsy, CT- or ultrasound-guided needle aspiration should be performed to confirm the pathological nature of the tumor, thereby facilitating optimal treatment planning. This multimodal diagnostic approach is especially critical for characterizing the tumor’s origin, size, histological type, vascular supply, and other key features. Notably, gross total resection of giant benign neurogenic tumors typically yields a favorable prognosis.

Keywords: Mediastinal Schwannoma; Pulmonary Atelectasis; Mediastinal Shift