Rare association of microfilaria with poorly differentiated mucin-secreting metastatic carcinoma in liver aspirate cytology

Filariasis, a neglected tropical disease (NTD), is mainly caused by nematodes—Wuchereria bancrofti, Brugia malayi and B. timori. Apart from profoundly disabling and disfiguring major clinical manifestations—lymphoedema, elephantiasis and hydrocoele—asymptomatic microfilaremia is common in endemic areas. Despite this, it is very rare to detect microfilariae in body fluids or aspirates. As per the literature search, this is the third case documenting incidental detection of microfilariae with metastatic deposits in the liver aspirate. Here, a 35-year-old man underwent image-guided fine-needle aspiration cytology of liver nodule. Liver aspirate cytology revealed poorly differentiated mucin-secreting metastatic carcinoma and coincidental presence of microfilariae of W. bancrofti. Recently, microfilaria has frequently been found to be associated with the debilitated, immunocompromised condition and various neoplasm/cancer/malignancy. Hence, meticulous investigation should be undertaken to search for hidden pathology, whenever microfilariae are detected; and to deeply scrutinise aspirates for such parasites always, especially in endemic regions.