An incidental diagnosis of an unusually located echinococcus alveolaris.

Hydatid cyst disease is a zoonotic infection caused by the genus Echinococcus. Hydatid cysts are usually located in the liver or lungs whereas the brain is an unusual location. A 45-year-old male patient was diagnosed with an intracranial mass suggesting a metastasis in the frontal region shown in the cranial computed tomography (CT) scan following a cranial trauma. The histological evaluation revealed an acellular laminated lesion surrounded with reactive changes, compatible with a cuticle. These findings were evaluated in favour of a hydatid cyst caused by Echinococcus multilocularis. Alveolar echinococcosis is a zoonotic disease caused by the genus Echinococcus multilocularis. Hydatid cyst is a common public health issue in the countries where livestock farming is common. Primary or metastatic tumours and abscesses should be considered in the differential diagnosis of hydatid cysts regardless of their location.