Illuminating the cytological intricacies of isolated filarial epitrochlear lymphadenitis: a case series of a seldom-seen clinicopathological occurrence with a review of the literature.

Background: Lymphatic filariasis is a major parasitic disease caused by Methods: A retrospective review of cytopathology archives from July 2023 to June 2025 was conducted to identify cases of isolated epitrochlear filarial lymphadenopathy. Clinical findings, hematological data, cytomorphological features, and treatment outcomes were compiled. All smears were re-evaluated independently by 2 cytopathologists. A literature search using major databases, including PubMed, Scopus, Web of Science, and Google Scholar, was performed to identify previously reported cases, which were tabulated for comparison. Results: Three patients aged 25-48 years (2 males, 1 female) presented with solitary, painless, firm epitrochlear swellings measuring 1.5-3 cm, without systemic symptoms or additional lymphadenopathy. FNAC revealed sheathed microfilariae in all cases: Discussion and Conclusion: Isolated epitrochlear lymphadenitis due to filarial infection is extremely uncommon and may be overlooked, especially in the absence of microfilaremia. This study underscores FNAC as a crucial diagnostic tool for detecting occult filariasis at atypical sites. Enhanced clinical suspicion and cytological evaluation in endemic regions can improve early diagnosis, guide timely therapy, and contribute to ongoing lymphatic filariasis elimination efforts.