Despite the improvement in the overall management of medulloblastomas in recent years, certain phenomena and in particular postoperative cerebellar swelling remain an enigma. This rare complication, little described in the literature, is nonetheless life threatening for the patients.

We report our experience about two children who developed severe cerebellar swelling with hydrocephalus and upward herniation soon after a gross total resection of a fourth ventricle medulloblastoma by a telo-velar approach. Despite rapid management of ventricular dilation and optimal medical intensive treatment of intracranial hypertension, both children died quickly after the surgery. Pathological examination analyses were in favour of anaplastic/large cell medulloblastoma.

Diffuse cerebellar swelling with upward herniation may occur postoperatively in young children with anaplastic/large cell medulloblastoma with leptomeningeal spread. In the literature, only 4 cases have been so far described with delayed onset of symptoms. Two children survived with an aggressive management (decompressive surgery and early radio-chemotherapy).

Cerebellar swelling is an unrecognised and sudden complication of posterior fossa surgery for metastatic anaplastic medulloblastoma with leptomeningeal dissemination in young children. An initial less invasive surgical approach could be considered in such cases, in order to prevent this complication with potentially tragic issue, and which cannot be managed with a CSF shunt alone.