Microfilaria in pleural effusion-an unusual presentation

Filariasis is endemic in many areas of tropical and subtropical countries. It is a public health problem in many countries including India. Filariasis has wide spectrum of presentation. The majority of cases in India are due to the infection caused by Wuchereria bancrofti. Infection caused by Wuchereria bancrofti is presented mainly in the form of hydrocele testis and lymphoedema. When it involves the lung, it presents as tropical pulmonary eosinophilia with pulmonary infiltrates and peripheral eosinophilia. Filariasis presenting as pleural effusion is an unusual finding. In this context, we report a case of an 80yr old male patient who presented with shortness of breath, fever and cough. Pleural fluid cytology revealed microfilaria in high density but the peripheral blood smear has not shown eosinophilia and microfilaria even after DEC provocation test, which is very rare.