Mature cystic teratoma of mediastinum with pleural effusion: An uncommon entity.

Teratomas are tumours composed of tissues originating from at least two of the three primitive germ layers, i.e., ectoderm, mesoderm and endoderm. A dermoid cyst, commonly known as benign cystic teratoma is a histological variant containing epidermis and its derivative (sebaceous material) within a lining of squamous epithelium. Mediastinum is the most common extragonadal site for germ cell tumours including mature teratomas. However, pleural effusion secondary to rupture of benign germ cell tumour is quite a rarity and the nature of pleural effusion in such ruptured cases has not been discussed in detail in literatures. Here, we are presenting a case of mature cystic teratoma coexistent with pleural effusion which is quite an uncommon entity making this case quite an interesting learning curve.