Thymoma-Associated Pleural Effusion Treated With Neoadjuvant Chemotherapy.

Anterior mediastinal masses, including thymomas, can present with thoracic symptoms or paraneoplastic syndromes, especially in adults over 40. Diagnosis involves imaging and biopsy, and treatment includes surgical resection and chemotherapy, depending on the stage. A 31-year-old male, with a history of alcohol use disorder and a former smoker, presented with increasing heartburn, shortness of breath, left shoulder pain, and chest pain. Imaging revealed an anterior mediastinal mass with pleural thickening and a small effusion. A biopsy confirmed a B2-type thymoma. Initial treatment included cyclophosphamide, doxorubicin, and cisplatin, resulting in significant tumor reduction and pleural effusion resolution. The patient underwent planned surgical resection following neoadjuvant chemotherapy. This case highlights the complexity of advanced thymoma treatment and the effectiveness of neoadjuvant chemotherapy in reducing tumor burden, the associated effusions, and improving outcomes. Continuous follow-up and further studies are essential to optimize treatment protocols for advanced thymoma.