Cervical tumor caused by the sexually mature stage of Fasciola hepatica

A 58-year-old man presented with an asymptomatic 5 cm left anterior cervical tumor that had been present for over a year. Histological analysis revealed chronic inflammation and granuloma with giant cells surrounding Fasciola hepatica eggs. Fas2 antigen was detected in the tissue by immunohistochemistry. Serology for F. hepatica was positive, but stool examinations were negative and eosinophil count was normal. A month later, the tumor recurred, and an adult parasite was found during excision. The patient received triclabendazole, and after 6 months serology was negative. Erratic localization of F. hepatica reveals a pathology involving chronic inflammation caused by a sexually mature parasite, although according to theory only immature parasites are located in ectopic lesions.