A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Human dirofilariasis is a mosquitoborne zoonosis predominantly caused by Dirofilaria repens nematodes in the Old World; breast involvement is uncommon and mimics breast neoplasia. We report a previously unpublished case from Israel. We also conducted a systematic review of histologically confirmed breast dirofilariasis cases retrieved from PubMed, Embase, and Scopus databases and from searching other literature. In total, we analyzed 40 breast dirofilariasis cases reported during 1959–2025. Most (95%, 38/40) patients were female; all were adults. Most cases were acquired in the Mediterranean rim (53%, 21/40) and India (15%, 6/40). Species-specific diagnosis was commonly made on the basis of morphology alone (37/40); those cases should be considered probable. The most common species was D. repens (n = 31); only 2 cases were molecularly confirmed. Excision was curative in all cases. Breast dirofilariasis should be considered in the differential diagnosis of solitary breast nodules in persons who live in or travel to endemic regions.
Dirofilariasis is caused by zoonotic filarial nematodes that primarily parasitize carnivores and are transmitted by various mosquito species depending on geographic distribution and Dirofilaria species ( 1 ). In human infections, the most commonly described species are D. immitis , which predominantly causes pulmonary dirofilariasis, and D. repens , D. tenuis , and D. ursi , which typically cause subcutaneous infections ( 1 ). The recently described D. asiatica , previously reported as Candidatus Dirofilaria hongkongensis, accounts for a further group of subcutaneous infections in Asia ( 2 ).
D. repens is the most frequently identified nematode species in human subcutaneous dirofilariasis, particularly in the Old World ( 1 ). Its primary vectors are mosquitoes of the Culicidae family, and the definitive hosts are typically canids and felids ( 3 ). The infection has been most commonly reported from Italy, India, Japan, and France ( 3 ). In most of those reports, the species was assigned on morphologic grounds, without molecular confirmation ( 3 ). The typical clinical manifestation of D. repens infection in humans is an isolated subcutaneous nodule, but rare cases also have worm maturation and microfilaremia ( 4 – 6 ). The upper body (head and neck) is the most common site of human D. repens infection; ocular and periocular sites alone account for ≈22% of all reported human dirofilariasis cases (subconjunctiva ≈16%, eyelid ≈7%) ( 3 ), but breast involvement is comparatively rare. We report a previously unpublished case of breast dirofilariasis from Israel. We also conducted a systematic review of the literature to assess breast dirofilariasis epidemiologic patterns, clinical manifestations, and diagnostic considerations.
In February 2010, an asymptomatic woman in her 50s with a history of benign breast cysts underwent routine annual mammography and breast ultrasound. Comparison with imaging performed 1 year earlier revealed no new abnormalities on mammography; however, ultrasonography identified a new 1.4-cm mixed-echogenic structure in the left breast. Two radiologists independ…