Five-year-old boy referred by his primary care paediatrician for a study due to a right frontoparietotemporal cranial deformity that had become more evident in recent months. He had presented occasional vomiting with bad smells, of one year's evolution, and headache accompanied by sonophobia and phonophobia, of variable frequency and mild intensity that had never woken him up at night since he was three and a half years old. The neurological examination was normal (including fundus examination), except for macrocephaly with a head circumference of 55 cm (>99th percentile).
The only significant family history is a left frontal kyphoplasty in the paternal grandfather.
Born of a controlled pregnancy, with normal prenatal ultrasound and uncomplicated euthecological delivery. He had no other personal history of interest. Psychomotor development was normal, with free walking at 13 months, language and sociability appropriate for his age, and he attended school with learning difficulties in reading and writing.
Cranial CT scan showed a large AQ in the right middle cranial fossa with midline displacement and collapse of the adjacent ventricular loops, which was confirmed by cranial MRI showing hypointense content in the right frontoparietotemporal region in T1 sequences and hyperintense in T2, which did not change after gadolinium contrast.

The patient was referred to neurosurgery, where intracranial pressures were monitored with a pneumatic epidural sensor, using a precoronal frontal trephine, and only the nocturnal pressures were found to be pathological. In view of chronic intracranial hypertension, treatment was decided with cystocysternostomy, communicating the QA with the optico-carotid cistern, by means of a 30° angled endoscope and a catheter with a double ventriculostomy balloon, to favour the communication of the spaces and free circulation of the CSF.