[Hydatid cysts of the brain stem. Two cases].

Cerebral hydatid cysts represent 2-3% of all intracranial masses in endemic countries. Its incidence in posterior fossa is very rare. We report two cases of brainstem location. Clinically, the lesion exhibited signs of brainstem tumor. In two patients, CT scan showed a hypodense lesion. There was no enhancement after contrast administration. One patient was explored by MRI; on precontrast images, the lesion appeared homogeneous with hyposignal intensity and smooth limits. T2 weighted MRI and post contrast examination confirmed the cyst nature of the lesion. Surgery was performed in the two patients. The cyst was first aspirated and its membrane was then removed. Post operatively, one patient died, the other one is still alive but severely affected two years later. CT scan showed total disappearance of the cyst. The clinical presentation, radiological findings and surgical procedures are discussed.