A case of pediatric primary osteolytic extradural and complicated hydatid cyst revealed by a skull vault swelling.

Hydatidosis is a parasitic infestation whose etiological agent is the larva of the cestode Echinococcus granulosus. It is a zoonosis, and the human being behaves as an accidental intermediate host in the parasitic cycle with pediatric predominance. The most frequent clinical presentation is hepatic, followed by pulmonary, with cerebral hydatidosis being extremely rare. Imaging is characteristic, generally dealing with single cystic lesion, usually unilocular and less frequently multilocular, located mainly intraaxially. Extradural hydatid cyst, whether primary or secondary, remains very rare or even exceptional. The primary disease remains extremely rare, and its clinical picture is related to the number, size, and location of the lesions. Infection within these cerebral hydatid cysts remains an extremely rare occurrence, and only few cases were reported previously in the literature. The authors report the nosological review of the clinical, imaging, surgical, and histopathological records of a pediatric primary osteolytic extradural and complicated hydatid cyst in a 5-year-old North African male patient coming from a rural area who presented for progressive onset of a painless left parieto-occipital soft swelling without any neurological disorder with good outcomes after surgery. The authors report this case due the fact that it had not been documented before in the pediatric population and to the success of the specialized treatment.