Symptomatic obstructive hydrocephalus caused by choroid plexus hyperplasia in a pediatric patient: illustrative case

BACKGROUND: Choroid plexus hyperplasia has been described as a rare cause of communicating hydrocephalus due to cerebrospinal fluid (CSF) overproduction. However, this is the first report of symptomatic obstructive hydrocephalus caused by mechanical obstruction of the aqueduct by a hyperplastic choroid plexus. OBSERVATIONS: A 4-year-old male presented with headaches and intermittent emesis. Magnetic resonance imaging (MRI) of the brain showed abnormal enlargement of the choroid plexus in the lateral ventricles with extension into the third ventricle, resulting in obstruction of the aqueduct of Sylvius, leading to obstructive hydrocephalus. Endoscopic third ventriculostomy (ETV) was chosen as the surgical treatment. During the procedure, high pressure flow of clear CSF was noted. Normal intraventricular anatomy was identified, and no cyst or tumor was found. The postoperative MRI showed a patent third ventriculostomy, without complication, and a significant decrease in supratentorial ventricular size. The patient was discharged 3 days after surgery with a complete resolution of symptoms. LESSONS: Choroid plexus hyperplasia has the potential to cause obstructive hydrocephalus, and it can be effectively treated with ETV. Our hypothesis is that the change in pressure caused by the procedure may have led to an uncorking of the aqueduct by the hyperplastic choroid plexus, contributing to the observed improvement.