Background <p>Mediastinal teratomas are germ cell tumors that most commonly arise in the anterior mediastinum. Although often asymptomatic and discovered incidentally, larger lesions may produce compressive respiratory symptoms. Trichoptysis is a rare but highly suggestive presentation.</p> Case Presentation <p>A 45-year-old woman presented with an 8-month history of chronic dry cough without dyspnea, sputum production, hemoptysis, or systemic symptoms. Chest radiography revealed a mediastinal opacity. Contrast-enhanced computed tomography (CT) of the chest showed a heterogeneous predominantly low-density mass in the left superior mediastinum with peripheral enhancement, inflammatory fat stranding, and mediastinal lymphadenopathy, raising concern for mediastinal abscess versus neoplasm. On the day of surgery, the patient recalled a prior episode of cough associated with expectoration of yellowish hair-like strands. Left posterolateral thoracotomy revealed a well-encapsulated anterior mediastinal mass densely adherent to the pericardium and left upper lobe. The lesion was excised en bloc with wedge resection of the adherent upper-lobe parenchyma. Histopathologic examination confirmed a mature mediastinal teratoma.</p> Case Discussion <p>Trichoptysis is an uncommon but strongly suggestive symptom of teratoma with airway communication. Imaging may be misleading when inflammatory changes are present, mimicking infection. Complete surgical excision remains the definitive treatment, and thoracotomy may be preferred when dense adhesions or lung involvement is anticipated.</p> Conclusion <p>Anterior mediastinal teratoma should be considered in patients with mediastinal masses and chronic cough, particularly when trichoptysis is reported. Complete resection offers excellent outcomes.</p>