Incidental detection of microfilariae in a lymph node aspirate: A case report

Lymphatic filariasis is a global health problem endemic in Nigeria. Peripheral blood smears are frequently negative for microfilariae in a significant number of infected patients in whom conventional diagnostic methods may also fail to identify the disease. In such cases, fine needle aspiration cytology may play an important role in disease identification. A 49-year-old South-western male Nigerian farmer, presented with a one-year history of a right groin swelling, which became painful 2 weeks before coming to the hospital. A clinical assessment of lymphogranuloma venereum was made to rule out a non-Hodgkin lymphoma. Initial laboratory investigations only showed mild eosinophilia and haematuria. However, fine needle aspiration cytology performed on the swelling showed microfilariae of Wuchereria bancrofti for which appropriate treatment was instituted with excellent outcome. This case demonstrates that lymphatic filariasis should be considered in the differential diagnosis of lymph node swellings in the groin and that aspiration cytology may play an important role in its diagnosis, especially in an endemic resource poor country.