Giant Mediastinal Teratoma Presenting with Recurrent Pleural Effusion and Respiratory Distress: A Case Report and Literature Review

Abstract

Mediastinal teratomas are rare germ cell neoplasms with an enigmatic histogenesis, harbouring tissues from all three embryonic germ layers. While predominantly gonadal in origin, their extragonadal manifestation in the mediastinum is an infrequent yet clinically significant anomaly. Most remain quiescent, detected incidentally, yet expansive lesions may exert profound mass effects, precipitating respiratory distress, dysphagia, and pleural effusions. In rare instances, rupture into the pleural or pericardial cavity can provoke life-threatening sequelae. We report the case of a 15-year-old female presenting with acute respiratory distress and a prior episode of spontaneous resolution. Imaging unveiled a voluminous anterior mediastinal mass exerting significant compression on adjacent structures, culminating in passive lung collapse. Surgical excision, though intricate due to extensive adhesions, was successfully accomplished. Postoperatively, the patient exhibited persistent partial lung collapse, necessitating intensive pulmonary rehabilitation. Histopathological analysis confirmed a benign cystic mature teratoma. This case underscores the criticality of early detection and surgical intervention in preventing catastrophic complications. Given their potential for malignant transformation and mass effect-related morbidity, mediastinal teratomas warrant vigilant clinical surveillance.