Mediastinal germ cell tumour masquerading as loculated pleural effusion.

Benign mediastinal teratomas often discovered while patients are still asymptomatic. Almost all arise in the anterosuperior mediastinal compartment. Most symptoms result from compression of adjacent structures. We report a case of a large teratoma arising from the anterior mediastinum that presented a confusing clinical picture of loculated pleural effusion which was successfully diagnosed and treated by surgical excision.