Egg and larvae of filarial worm in fine-needle aspiration smears of lymph node

Filariasis is a major health problem in tropical countries like India. Detection of egg with or without larva in fine-needle aspiration cytology (FNAC) is very unusual despite the high incidence of this parasite in endemic zone. Early diagnosis and treatment prevent the more severe manifestations of disease. A 6-year-old male from eastern Uttar Pradesh presented with the complaints of axillary swelling, fever and loss of appetite. On examination, swelling was 3 cm x 2 cm in size, freely mobile, firm and non-tender. FNA was performed and airdried smears were stained with Giemsa stain. Smears showed many short and blunt larvae without any distinct sheath and nuclei. Numerous round to oval eggs with short coiled larvae inside them were also seen. A diagnosis of filarial lymphadenopathy was made. The case was considered worth documentation to highlight the finding of filarial eggs in FNA of lymph node, which can be missed or misdiagnosed by an unexperienced pathologist leading to delayed or wrong treatment of a curable disease.