Catamenial haemothorax-A rare cause of pleural effusion.

Common causes of haemorrhagic pleural effusions include malignancy (primary or metastatic), tuberculosis, pulmonary embolism, collagen vascular diseases, trauma and iatrogenic causes. Clinical history along with pathologic, microbiologic and biochemical evaluation of pleural fluid confirms the diagnosis in most cases. However, if there is recurrent haemorrhagic effusion without corroborative history or mass lesion in lung, or evidence of microorganisms, then we should think of uncommon causes.