Pseudo-Tumor of the Epididymis, a Rare Clinical Presentation of Human Dirofilaria repens Infection: a Report of Autochthonous Case of Dirofilariasis in Southwestern Slovakia

Abstract

Purpose: Dirofilariasis caused by the filarial nematode Dirofilaria repens is mainly a disease of dogs and other carnivores. Also, humans can be accidentally infected with this parasite. The infective third-stage filariform larvae are transmitted by various species of mosquitoes. Until this day, a total of 17 human cases caused by D. repens have been diagnosed in Slovakia, 11 subcutaneous, 4 ocular, 1 pulmonary and 1 in the epididymis. The aim of this report was to describe an unusual clinical case of dirofilariasis of the scrotum. Methods: Extirpated worm was subjected to the molecular and histological identification. PCR for the amplification of cytochrome oxidase subunit 1 (CO1) was performed using specific D. repens primer pair. Results: Here we document the 13th case of human dirofilariasis in a 46-year-old man from southwestern Slovakia. Very rare in humans, genital involvement manifests itself as pseudotumor nodule affecting the epididymis. The patient consulted a general practitioner due to a palpable subcutaneous lump in the scrotum. Routine laboratory analysis revealed blood eosinophilia (16.6%). The ultrasound examination was indicated, and subsequently, surgical excision of the right epididymal nodule was performed. On the basis of histological microscopic examination and PCR-based detection, the helminth was identified as Dirofilaria repens. This represents the ninth case of autochthonous dirofilariasis in Slovakia. Conclusions: The majority of D. repens infections were recorded in southwestern regions of Slovak Republic, which are considered to be endemic areas for canine dirofilariasis. Our described patient also comes from southwestern part of Slovakia (Topoľníky, Dunajská Streda region).