Teratoma masquerading as catamenial pleural effusion.

Pleural effusion is a common clinical entity in medical practice. We report a case wherein extensive investigations failed to yield a diagnosis and medical management including repeated thoracocentesis left the effusion refractory. The patient, a 26 years lady, gave a definite history of catamenial dry cough and wheeze. The mystery was unraveled following exploratory thoracotomy when a giant mediastinal teratomatous cyst with luteinized ovarian tissue was discovered and removed, leading to eventual cure for the patient.