OTHR-12. ANEURYSMAL BONE CYST RESEMBLING A POSTERIOR FOSSA TUMOR

We presented the case of a 6-year-old boy who was seen in the emergency room because of signs of intracranial hypertension and left cerebellar syndrome. The CT scan revealed a heterogeneous lesion within the left hemisphere displacing the fourth ventricle and eroding the occipital bone. The MRI showed the same heterogeneous lesion majorly cystic, involving the bone and displacing the left cerebellar hemisphere. A minor hydrocephalus was evident in both studies. A suboccipital craniectomy was done and a cystic epidural tumor remodeling and eroding the bone was noted. The histopathological diagnosis corresponded to an aneurysmal bone cyst. Aneurysmal bone cyst is a rare benign tumor accounting for 3–6 % of tumors of the cranial base. We discuss the unusual location of the lesion.