Human Dirofilariasis Presenting as Scrotal Mass

Abstract

Surgery Unit complaining a painless nodule on his left hemi scrotum (ASM). He had neither pathological history nor was in contact with dogs or other animals and never visited other countries.The physical examination revealed no pathological findings except for a single painless hard nodule of 1 cm at the apex of the scrotum with any connection to the testis. The skin over the nodule was normal without any signs of inflammation and the inguinal lymph nodes were not palpable Routine laboratory tests of the blood showed no abnormal values for the age. Tumors markers as βHCG and α-fetoprotein were within normal range.Suspecting an extra-testicular neoplasm an ultrasound scan with high-resolution linear probe 10 -12 MHz of the nodule was performed. It showed the presence of an anechoic cystic formation without any vascularization in its contest or vascular pole at the color-doppler integration. Within a cyst mass a tubular coiled structure with parallel echogenic wall in continuous movements was found: to identify the species of worm specialist opinion was requested.The characteristic pattern movements of the nematode (filaria dance sign-FDS) led to diagnosis of human subcutaneous dirofiliasis (HSD). Testicular tissue was normal.(FIGURE 1).The surgery was performed under general anesthesia with minor surgery approach by a transversal scrotal incision of less than 1 cm over the nodule. The mass wasn't in connection with testicular or funicular structures. It was isolated from the dartos without any damage to the capsule and was enucleated intact (FIGURE 2).The hystopathological examination showed a simil-cystic structure with granulomatous inflammatory wall with a high number of eosinophils and a tubular structure of 10 cm of length inside moving when placed in physiological solution (FIGURE 3).The diagnosis of infection from Dirofilariarepens was based on the morphological characteristic of the worm that displayed the tipical features of a female. AbstractA large spectrum of pathology may present in children as an asymptomatic scrotal mass (ASM) ranging from congenital to neoplastic lesions.We observed a 11 months old child referred to us for suspicion of neoplasm presenting with an asymptomatic scrotal mass.High frequency scrotal sonography enabled diagnosis of nematode infection (Dirofilaria repens): viability of the adult worms was assessed by looking for the animated documentation of filarial dance sign (FDS).Differentiation from malignancy allowed an appropriate management consisting in minor surgery.Human Subcutaneous Dirofilariasis (HSD) is an endemic zoonosis spread throughout the world, with dogs and cats being the definitive host for this parasite. Human infections caused by Dirofilaria repens have been reported in Eastern Europe, Mediterranean area, central and Southern Asia, transmitted by various species of mosquitoes and usually presented as subcutaneous nodule.Extra-testicular pathologies are encountered relatively infrequently but awareness of different possible etiology avoids unnecessary extensive s...