LAUSR

Filariasis is mainly a disease of tropics, which is caused by two nematodes Wuchereria bancrofti and Brugia malayi. They are responsible for 90% and 10% of the cases and are transmitted by Culex and Mansonia mosquitoes, respectively. Most commonly patients present with fever, asymptomatic microfilaraemia followed by acute adenolymphangitis, lymphatic obstruction, chronic lymphatic disease, and tropical pulmonary eosinophilia. On cytology, microfilaria has been described at various body locations in several case reports, however, their description in effusion fluid and specifically in ascitic fluid is relatively sparse and they are mostly described to be associated with malignancy. Herein, we present one case of microfilaria in the ascitic fluid sample. A 44-year-old male presented with tense ascites with a clinical diagnosis of chronic liver disease. The ascitic fluid was sent for the cytological examination for malignant cells. A total amount of 5 mL straw-colored fluid was received in the department of cytology. Two smears were made by liquid-based preparation (SurePath) and were stained with Papanicolaou’s stain. The smears showed many microfilariae along with polymorphs, reactive mesothelial cells, and few lymphocytes (Figure 1A-C). The microfilariae were sheathed with a row of nuclei not extending up to the tail end suggesting the morphology ofW. bancrofti. The sheath of the parasite was clear with somatic cells in the body. The head end was blunt with cephalic space as long as well as broad (Figure 1C). Microfilaria in the ascitic fluid is usually associated with chylous ascites due to lymphatic obstruction in the retroperitoneal channel. The gross feature of the fluid in such cases is characteristic and gives a warning signal to search microfilaria on microscopy. In contrast, the present case showed only straw-colored fluid along with large number of microfilaria. This was an unexpected finding. Microscopic examination in low power is essential in such cases otherwise the parasite can be overlooked. The parasite may often be misinterpreted as cotton thread or other linear foreign bodies. However, careful examination reveals the sheathed structure with multiple nuclei. The exact mechanism of such a chylous ascites and microfilaria in the fluid is unexplainable. Possibly, there is a partial obstruction in the retroperitoneal lymphatic drainage in this case.