Microfilaria in a patient of achylous hematuria: A rare finding in urine cytology.

Filariasis is a widespread public health problem seen commonly in tropical countries. Microfilariae have been reported in aspiration smears from various sites. However, it is very rare to detect these organisms in voided centrifuged urine cytology. We, report this rare finding in a 25-year-old patient who presented with achylous hematuria.

Introduction

Filariasis is a general public health problem seen commonly in tropical countries like India. It is caused mainly by three species—Wuchereria bancrofti, Brugia malayi and Brugia timori. In India, W. bancrofti is the commonest and B.timori is the rarest. Filariasis has been reported in cytologic smears from various organs and sites like male genital organs, thyroid, breast, lymph node, liver, soft tissue swellings, bone marrow, cervical smears, body fluids etc.[1-7] Detection of microfilaria in voided urine sediment, especially in achylous hematuria specimen, is extremely rare. We report a case with microfilariae of W. bancrofti in a 25-year-old patient who presented with achylous hematuria.

Case Report

A 25-year-old male patient presented in urology out-patient department (OPD) with history of intermittent painless hematuria for three weeks. There was no history of fever, trauma, instrumentation, flank pain, ureteric colic or passage of milky white urine. There were no lower urinary tract symptoms (LUTS). On general examination, there was no hepatosplenomegaly or lymhadenopathy. Local examination including genitalia did not reveal any abnormality. Routine hemogram was normal. The peripheral smear examination did not reveal any parasite. A voided urine sample was collected and sent to the cytopathology laboratory for routine cytological examination. Urine sample was processed by centrifuging at 3000 rpm for 3 minutes. The sediment smears made were stained with May–Grünwald–Giemsa (MGG) and Papanicolaou stains. Smears revealed urothelial cells along with neutrophils, lymphocytes, red blood cells and few microfilariae [Figure 1]. No malignant cells were seen. High power examination of the microfilaria showed a sheathed parasite with central axis of nuclei which ended abruptly before the tip of tail [Figure 1]. With this, characteristic morphology the microfilariae were identified as W. bancrofti.

Figure 1

Photomicrograph of urine sediment showing a sheathed microfilaria with central axis of nuclei ending abruptly before the tip of tail along with few urothelial cells, inflammatory cells and red blood cells (MGG, ×400)

Subsequent to the cytological diagnosis patient was treated with 21 days course of diethylcarbazine (DEC) after which he became asymptomatic.

Discussion

W. bancrofti accounts for majority of the filarial infection in India; accounting for approximately 95% of cases. Infection by this sheathed species is commonly seen in India, China, Indonesia and Eastern Pacific.[8] Filariasis may present with various clinical manifestations, the commonest being asymptomatic. The common presentations include microfilaremia, lymphedema, hydrocele, acute adenolymphangitis (ADL), chronic lymphatic disease and less common presentations are like chyluria and tropical eosinophilia. Achylous hematuria is a very rare presentation. Almost all persons with filariasis, however, have microscopic hematuria and/or protienuria. Shedding of microfilaria in urine is possibly determined by local factors like inflammation, trauma or stasis, which mainly affect the lymphatics and small vessels causing either lymphatic blockage or damage to the vessel wall.

To the best of our knowledge, only few cases of W. bancrofti have been reported in voided urine sample in literature. In most of these reported cases, there was a history of chyluria.[45] There are only occasional case reports in which patient presented with haematuria. Webber et al.[1] first reported microfilaria in a 23-year-old male patient during a routine workup for intermittent painless hematuria. They detected W. bancrofti in both voided and catheterized urine sample. Vankalakunti et al.[2] reported W. bancrofti in a 45-year-old man who presented with painless hematuria and clinical suspicion of malignancy.

In the present case, microfilaria was incidentally detected in a voided centrifuged urine sample of a young male patient who presented with complaints of intermittent painless hematuria. There was no history of chyluria and routine hemogram was normal. Urine sediment also showed mild reactive atypia in the urothelial cells. The explanation of non-chyluric hematuria may be that significant lymphatic obstruction may not have taken place; therefore, patient did not present with chyluria.

The microfilaria can be detected in blood, various body fluids, fine needle aspiration smears and histological examination as well as by serological and immunological tests. Among these, ELISA and rapid – format immunochromatographic card test have a very high sensitivity and specificity.[8] Detection of parasite DNA by polymerase chain reaction (PCR) is now considered as the most sensitive technique for definite diagnosis of this infection. Diethylcarbamazine (DEC, 6 mg/ kg daily for 12 days) remains the treatment of choice for the individual with active infection even after many decades since it was first used in W. bancrofti infection. The drug has both macro- and microfilaricidal properties.

To conclude, detection of microfilaria in urine without chyluria is rare. Most of the infected individuals do not have microfilaremia at the time of clinical manifestation, and definitive diagnosis in such cases can be difficult. Careful screening of the urine sample helped to detect this totally curable infection. It saved the patient from undergoing the trauma of invasive investigations and prevented further complications.