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Year : 2019  |  Volume : 12  |  Issue : 3  |  Page : 267-269  

Liquid-based cytological diagnosis of achylous unilateral bancroftian pleural effusion: An uncommon presentation of a common problem

1 Department of Pathology, UP University of Medical Sciences, Etawah, Uttar Pradesh, India
2 Department of Pathology, Rohilkhand Medical College, Bareilly, Uttar Pradesh, India

Date of Submission19-Aug-2018
Date of Acceptance04-Feb-2019
Date of Web Publication15-May-2019

Correspondence Address:
Megha Ralli
Department of Pathology, UP University of Medical Sciences, Saifai, Etawah - 206 130, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mjdrdypu.mjdrdypu_132_18

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Lymphatic filariasis is endemic and common in India. Filariasis is a widespread public health problem seen commonly in tropical countries. Filarial organism can be detected in cytological smears from various sites of the body in clinically unsuspected cases of filariasis. Incidental detection of filarial organism has been reported in cytological smears from almost any part of the body; however, it is very rare to detect these organisms in achylous hemorrhagic pleural fluid specimen. Demonstration of microfilaria in liquid-based cytological smears is rarely reported. To the best of our knowledge, the present case of achylous bancroftian pleural effusion diagnosed on liquid-based cytology (LBC) is the first one from the Indian subcontinent. We report a case with microfilariae of Wuchereria bancrofti in an 80-year-old male patient who presented with achylous, hemorrhagic unilateral pleural effusion in LBC.

Keywords: Cell block preparation, filariasis, liquid-based cytology, pleural effusion, Wuchereria bancrofti

How to cite this article:
Pandey P, Ralli M, Agarwal S, Agarwal R. Liquid-based cytological diagnosis of achylous unilateral bancroftian pleural effusion: An uncommon presentation of a common problem. Med J DY Patil Vidyapeeth 2019;12:267-9

How to cite this URL:
Pandey P, Ralli M, Agarwal S, Agarwal R. Liquid-based cytological diagnosis of achylous unilateral bancroftian pleural effusion: An uncommon presentation of a common problem. Med J DY Patil Vidyapeeth [serial online] 2019 [cited 2022 Dec 5];12:267-9. Available from: https://www.mjdrdypv.org/text.asp?2019/12/3/267/258199

  Introduction Top

Filariasis is a major social and economic scourge in tropics and subtropics of Africa, Asia, Western Pacific, and parts of America affecting over 120 million people in 80 countries. The disease is endemic all over India, but nine Indian states (Andhra Pradesh, Bihar, Gujarat, Kerala, Maharashtra, Orissa, Tamil Nadu, Uttar Pradesh, and West Bengal) contribute to about 95% of the total burden.[1],[2]

Microfilariae found in humans are mainly divided under two categories, i.e., sheathed and unsheathed. Amongst sheathed ones are Microfilaria bancrofti, Microfilaria malayi, and Microfilaria loa, while unsheathed ones are Microfilaria perstans and Microfilaria ozzardi are the unsheathed variety.

The microfilaria bancrofti was detected by aspiration cytology at so many different sites such as breast, thyroid, liver, lungs, lymph nodes, and a small number of cases have been reported in bone marrow and body fluids, but the development of pleural effusion is an uncommon manifestation of filariasis and such effusions tend to be chylous in nature due to leakage of chyle from the occluded thoracic duct.[3],[4],[5] Demonstration of microfilaria in liquid-based cytological smears is rarely reported. To the best of our knowledge, the present case of achylous bancroftian pleural effusion diagnosed on liquid-based cytology (LBC) is the first one from the Indian subcontinent.

  Case Report Top

An 80-year-old nondiabetic, normotensive male with a history of smoking for 30 years, a resident of Saifai, Uttar Pradesh, India, presented with chief complaints of pain chest, breathlessness, cough, fever, and malaise for 15 days. Physical examination revealed a right-sided pleural effusion with reduced chest expansion, stony dull percussion, and reduced breath sounds. He was investigated on the lines of nonresolving pleural effusion keeping the differential diagnosis of tuberculosis and malignancy. Chest X-ray revealed right-sided pleural effusion while the left side was unremarkable. The Mantoux test showed no induration. Sputum examination for acid-fast bacilli (AFB) on three occasions was negative. A pleural tap was performed, and hemorrhagic fluid was aspirated. AFB were not detected in the direct smears prepared from the fluid, and the culture for Mycobacterium tuberculosis was negative. Pleural fluid was sent to cytopathology laboratory for fluid cytology. Hemorrhagic pleural fluid was processed for LBC and cell block preparation.

Cytopathological features

Papanicolaou- and May-Grünwald-Giemsa-stained slides prepared by LBC [Figure 1]a, [Figure 1]b, [Figure 1]c, [Figure 1]d revealed a large number of microfilariae, identified as Wuchereria bancrofti because of the presence of hyaline sheath; cephalic space length:breadth ratio was 1:1, nuclei were almost spherical, regularly placed, appeared in regular row, well separated without any overlapping, and were absent at the tip tail. Numerous reactive mesothelial cells and a few lymphocytes were seen in the background. No evidence of malignancy was identified. Cell block stained by hematoxylin and eosin stain [Figure 2]a and [Figure 2]b also showed numerous microfilariae.
Figure 1: Liquid-based cytology preparation of pleural fluid (a and b) revealed large number of microfilariae of Wuchereria bancrofti along with numerous reactive mesothelial cells and (c and d) sheathed microfilaria of Wuchereria bancrofti with a clear space free of nuclei at the caudal end along with reactive mesothelial cells and few lymphocytes (a: Papanicolaou stain, ×100; b: May-Grünwald-Giemsa ×100; c: Papanicolaou stain ×400; d: May-Grünwald-Giemsa ×100)

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Figure 2: (a and b) Cell block preparation revealed numerous microfilariae (black arrows), mesothelial cells (thick arrows), and hemorrhage (Hematoxylin and eosin stain, ×400). (c) Peripheral blood film revealed microfilaria of Wuchereria bancrofti in the background of formed elements of blood (Leishman stain, ×100). (d) High-power view of sheathed bancroftian microfilaria in peripheral blood film (Leishman stain, ×400)

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With the cytomorphological diagnosis of filarial pleural effusion, the patient had nocturnal blood examination, which revealed numerous microfilariae [Figure 2]c and [Figure 2]d. As a routine practice followed in our laboratory, conventional smear of fluid was also prepared which showed microfilaria admixed with few inflammatory cells against proteinaceous background [Figure 3].
Figure 3: Smear showing microfilaria admixed with few inflammatory cells against proteinaceous background (May-Grünwald-Giemsa, ×200)

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LBC was prepared in our case for academic interest. The patient's routine blood investigation showed absolute eosinophilia with raised total leukocyte count. Indirect enzyme-linked immunosorbent assay (ELISA) was performed which was highly positive for specific recombinant W. bancrofti filarial antigen (WL-L2). Subsequent to the cytological diagnosis, the patient was treated with 21-day course of diethylcarbamazine (DEC) after which he became asymptomatic.

  Discussion Top

In India, the prevalence of lymphatic filariasis is quite high (5%–10%), of which 98% of the diagnosed cases are caused by W. bancrofti.[2] Filariasis may present with various clinical presentations, including fever, asymptomatic microfilaremia, lymphatic obstruction, and tropical pulmonary eosinophilia (TPE). Some infected individuals remain asymptomatic throughout their life in endemic zones traditionally called as “endemic normal.”[6]

Common methods of diagnosis of filariasis are by demonstration of microfilaria in stained or unstained blood films, circulating filarial antigen detection, and demonstration of organism in histopathological sections. LBC is rarely applied for even routine diagnosis of clinically suspected filariasis. Incidental detection of filarial organism has been reported in cytological smears from almost any part of the body. Microfilaria is the most common form of filarial organism detected in cytological smears; however, ova of the organism and fragments of adult worm can also be detected rarely.[7] Thus, role of LBC in diagnosis of filarial pleural effusion cannot be underestimated in clinically unanticipated cases.

Isolated pleural effusion due to filariasis is an uncommon presentation.[3],[4],[5] Lymphedema, hydrocele, elephantiasis, and chyluria are the features of chronic filariasis. Nonchylous pleural effusions caused by microfilariae are rare, as in our case, it was hemorrhagic. Moreover, no other associated pathological condition was found in our case as present in cases reported by Gupta et al.[8]

In India, the most common cause of pleural effusion is tuberculosis, and therefore, this was the first diagnosis considered. Malignancy is the most common cause of hemorrhagic pleural effusion seen with malignancy of the lung and breast and lymphoma or as adenocarcinoma from occult primary.[9]

Shedding of microfilaria in pleural fluid is possibly determined by local factors such as inflammation, trauma, or stasis, which mainly affect the lymphatics and small vessels causing either lymphatic blockage or damage to the vessel wall.[10] In our case, there was no history of lymphedema, hydrocele, lymph scrotum, chyluria, TPE, adenopathy, and hematuria. Pleural fluid also showed mild reactive atypia in the mesothelial cells. The explanation of nonchyluric pleural effusion may be that significant lymphatic obstruction may not have taken place; therefore, the patient did not present with chylous effusion.

Among various tests, ELISA and rapid-format immunochromatographic card test have a very high sensitivity and specificity.[5] Detection of parasite DNA by polymerase chain reaction is now considered as the most sensitive technique for definite diagnosis of this infection. 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.

  Summary Top

Detection of microfilaria in achylous pleural effusion is rare. Most of the infected individuals may not have microfilaremia at the time of clinical manifestation, and definitive diagnosis in such cases can be difficult. Careful screening of the effusion sample helped to detect this totally curable infection. It saved the patient from undergoing the trauma of invasive investigations and prevented further complications. Thus, role of cytology in diagnosis of filariasis cannot be underestimated in clinically unanticipated cases. This study is an attempt to prove importance of LBC in diagnosis of filariasis.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Mitra SK, Mishra RK, Verma P. Cytological diagnosis of microfilariae in filariasis endemic areas of Eastern Uttar Pradesh. J Cytol 2009;26:11-4.  Back to cited text no. 1
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Pandey P, Dixit A, Chandra S, Tanwar A. Cytological diagnosis of bancroftian filariasis presented as a subcutaneous swelling in the cubital fossa: An unusual presentation. Oxf Med Case Reports 2015;2015:251-3.  Back to cited text no. 2
Akhtar S, Gumashta R, Gumashta J. Delayed diagnosis bancroftian filarial pleural effusion. Prog Health Sci 2012;2:207-10.  Back to cited text no. 3
Yelikar BR, Potekar RM, Mahesh KU, Patil VS. Filariasis presenting as non resolving pleural effusion. Int J Biol Med Res 2012;3:2284-6.  Back to cited text no. 4
Aggarwal J, Kapila K, Gaur A, Wali JP. Bancroftian filarial pleural effusion. Postgrad Med J 1993;69:869-70.  Back to cited text no. 5
Jha A, Shrestha R, Aryal G, Pant AD, Adhikari RC, Sayami G, et al. Cytological diagnosis of bancroftian filariasis in lesions clinically anticipated as neoplastic. Nepal Med Coll J 2008;10:108-14.  Back to cited text no. 6
Jain S, Sodhani P, Gupta S, Sakhuja P, Kumar N. Cytomorphology of filariasis revisited. Expansion of the morphologic spectrum and coexistent with other lesions. Acta Cytol 2001;45:186-91.  Back to cited text no. 7
Gupta K, Sehgal A, Puri MM, Sidhwa HK. Microfilariae in association with other diseases. A report of six cases. Acta Cytol 2002;46:776-8.  Back to cited text no. 8
Marathe A, Handa V, Mehta GR, Mehta A, Shah PR. Early diagnosis of filarial pleural effusion. Indian J Med Microbiol 2003;21:207-8.  Back to cited text no. 9
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Chatterjee KD, editor. Phylum nemathelminthes: Class nematoda. In: Parasitology (Protozoology and Helminthology) in Relation to Clinical Medicine. 12th ed. Kolkata: Chatterjee Medical Publishers; 1980. p. 184-99.  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3]


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