Choroid Plexus Papilloma

Clinical History

boy was referred to the hospital because of progressive tremor of the right hand. Neurological investigations revealed an intention tremor and slight ataxia. Fundoscopic examination showed papiledema. Subsequently CT scan and angiography were performed.

Imaging Findings

An 8-year-old boy was referred to the hospital because of progressive tremor of the right hand. Neurological investigations revealed an intention tremor and slight ataxia. Fundoscopic examination showed papiledema. Subsequently CT scan and angiography were performed.

Discussion

Choroid plexus papillomas are rare tumors of neuroectodermal origin, representing 0.5 to 0.6% of all intracranial neoplasms. They occur predominantly in the first decade of life, especially in the first two years. Choroid plexus papillomas bulge into the ventricular cavity and are therefore primarily intraventricular. The most common site of origin in the pediatric age group is within the atria of the lateral ventricles, and in adults within the fourth ventricle. These tumors usually do not invade the brain. Clinical diagnosis is difficult because of non specific signs and symptoms. Symptomatology is related to CSF pathway obstruction with intracranial hypertension. Most of the patients with choroid plexus papilloma have hydrocephalus, probably due to overproduction of cerebrospinal fluid by the tumor itself. The diagnosis of choroid plexus papilloma is suggested by the findings of hydrocephalus and an intraventricular space occupying lesion which does not produce obstruction. On CT scan the typical choroid plexus papilloma appears as a well marginated, smooth or lobulated iso- or high-density mass protruding into the lumen of the ventricle with strong contrast enhancement. This marked homogeneous enhancement is related to the highly vascular nature of the tumor. Tumoral calcifications are uncommon in the pediatric age group. Choroid plexus papilloma and intraventricular meningeoma cannot be differentiated by CT characteristics. The MRI characteristics are of intermediate signall intensityI on T1- and intermediate or increased signal intensity on T2-weighted images. There are areas of internal signal void, predominantly curvilinear, indicating enlarged intratumoral vessels. MRI is superior to CT in assessing intraventricular location and extension of the tumor, because of its multidirectional imaging capabilities. At angiography, enlargement of choroid arteries and multiple small tortuous vessels in the arterial phase are characteristic. In the capillary and venous phases, strong homogeneous accumulation of contrast medium in the tumor is seen. Differential diagnosis includes meningeoma, ependymoma and choroid plexus carcinoma, the latter usually shows a more invasive growth. Except by location and concomitant hydrocephalus, choroid plexus papillomas cannot reliably be differentiated from these tumors on the basis of CT characteristics alone.

Differential Diagnosis List

Final Diagnosis

Choroid plexus papilloma

URL:	https://www.eurorad.org/case/864
DOI:	10.1594/EURORAD/CASE.864
ISSN:	1563-4086