An unusual presentation of an encapsulated adult Wuchereria bancrofti worm in eyelid subcutaneous tissue

Case A 65-year-old female presented with swelling in the right upper eyelid for 3 weeks. She reported an insect bite at the same location 3 weeks back [Figure 1].Figure 1: Patient after initial medical treatmentOn examination, a round, firm, mobile, nontender mass was palpated in the right superomedial orbit. It was not attached to the skin or surrounding structures. Valsalva, transillumination, and retropulsion tests were negative. Ocular movements were full, with no proptosis, bruit, or sensory deficits. No lymphadenopathy was noted. Computed tomography scan of the orbit and brain revealed a nodular, round, hyperdense mass in the right superomedial orbit [Figures 2 and 3].Figure 2: Computed tomography scan coronal view, showing round, nodular, hyperdense massFigure 3: Computed tomography scan sagital view, showing round, nodular, hyperdense massThe patient underwent an excision biopsy [Figure 4].Figure 4: Mass of size 1 cm × 1 cm, firm, solid, well encapsulated was removedHistopathology confirmed an encapsulated filarial worm [Figure 5]. Slides showed an encysted adult parasitic worm with a double-barreled uterus and developing larvae [Figure 6]. Sections demonstrated longitudinal and transverse cuts of adult worms possessing a sheath and containing organelles and eggs. Surrounding tissue exhibited intense inflammation with foreign body giant cells and fibrosis [Figure 7].Figure 5: H and E, ×10 showing Classic double barrel uterus of adult female worm with developing larvae (microfilarae) with adjacent inflammatory responseFigure 6: H and E, ×40 showing Classic double barrel uterus of adult female worm with developing larvae (microfilarae)Figure 7: H and E, scanner view showing Classic foreign body with adjacent inflammatory responseShe was treated with oral diethylcarbamazine 100 mg thrice daily for 14 days.[1] Discussion Our histological findings were compared with various other helminths.[2] For example, Trichinella spiralis larvae are typically observed within muscle cysts. Schistosoma species present with calcified eggs; whereas Echinococcus and Taenia species show hooklets and fluid-filled cysts. On the contrary, our case involved an adult worm in subcutaneous tissue. Helminths presenting as subcutaneous nodules include Onchocerca volvulus, Mansonella streptococca, and Loa loa, but these infections are rare in India. Cases of subcutaneous infections, caused by Dirofilaria repens, are also being reported.[3] A case of Brugia malayi presenting with a periorbital nodule in Thailand has also been reported.[4] Lymphatic filariasis affects over 120 million people globally, with 70% of cases in India, Nigeria, Bangladesh, and Indonesia.[5] India alone accounts for nearly 40% of global cases.[5] Bancroftian filariasis involving the conjunctiva, anterior chamber, retina, uvea, and vitreous has also been reported.[6] Bancroftian filariasis presenting as subcutaneous nodules, like our case, is exceedingly rare. Data availability statement Data available on request due to privacy/ethical restrictions. 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. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.