Benign cystic mediastinal teratoma presenting as a massive pleural effusion in a 17-year-old boy

Mediastinal teratomas are a rare, albeit an important differential diagnosis of anterior/middle mediastinal masses in young adults and various atypical presentations have been reported. The authors report a case of a 17-year-old boy who presented with a 2-month history of worsening shortness of breath and pleuritic chest pain. A massive left-sided pleural fluid collection was seen on a chest radiograph (CXR). The pleural fluid was drained and a CT Thorax confirmed the presence of a cystic mass. Following re-accumulation of the fluid, thoracotomy was performed and a benign mediastinal teratoma excised. The patient remained well with no evidence of recurrence on follow-up CXRs a year post operatively.