Incidental detection of filaria in fine-needle aspirates: a cytologic study of 14 clinically unsuspected cases at different sites.

Filariasis is a major health problem in tropical countries like India. Detection of microfilariae or adult worm or egg in FNAC is very unusual despite the high incidence of this parasite in endemic zone. The aim of this study was to document the value of fine-needle aspiration cytology (FNAC) in diagnosis of filaria at all possible sites presenting as mass or swelling. Fourteen patients (nine males and five females) in the age range of 14-61 years were subjected to FNAC. FNA from swellings was done using 22-gauge needles fitted with 10 or 20 ml disposable plastic syringes. The slides were stained with May-Grunwald-Giemsa stain, Haematoxylin and Eosin (H&E) stain, and Papanicolaou (Pap) stain. In total, 14 cases of filariasis were detected, which included subcutaneous swellings (six cases), epididymis/spermatic cord nodules (four cases), breast lumps (two cases), lymph nodes (one case), and thyroid swelling (one case). Larvae (microfilariae), eggs, and adult worms were detected in cytological smears. Microfilaria was present in all 14 cases whereas adult worm was found in three cases only. In four cases, eggs were seen in the smears. None of the patients was microfilariaemic and significant eosinophilia (>10%) was seen seen in two patients. Filarisis should be considered as one of the differential diagnosis of swelling in endemic area. Identification of the parasite, Wuchereria bancrofti, in FNA smears and accurate diagnosis of filaria is important to employ proper treatment. Early diagnosis and treatment prevents the more severe manifestation of the disease, lymphatic filariasis.