human dirofilaria repens infection of the breast: a case report

background: dirofilariasis is a common helminthic parasitic disease in both domestic and wild animals around the world, with canines as the principal reservoir host and mosquitoes as the vector.  human dirofilariasis has been reported from many parts of the world, including africa, australia, the americas, europe, and asia. case report: a 40 year old woman from abadan city southwest of iran referred to surgeon with a nodule on her right breast. ultrasound and mammography revealed a nodule diagnosed as parasitic lesion. after resection of the nodule, tissue was placed in 10% formaldehyde and sent to pathology laboratory. in histopathological examination, cross section of a worm surrounded with necrotic tissue, associated with infiltration of neutrophils, eosinophils, and foreign body giant cells observed which was morphologically compatible with dirofilaria repens. conclusion: human dirofilariasis should be considered in endemic regions.