Choroid plexus tumor is a rare occurrence in general practice. Both benign (papillomas) and malignant (carcinomas) variants exist, with the benign type being much more common. They are mainly identified in younger children, but individuals of any age can develop choroid plexus tumors. Symptoms and signs are related to the accumulation of cerebrospinal fluid and raised intracranial pressure and include vomiting, visual changes, seizures, bulging fontanelles, strabismus, and various neurological deficits. Imaging studies are crucial for the diagnosis, but a histopathological examination is often necessary to discriminate between benign and malignant tumors.
The vast majority of patients who develop choroid plexus tumor are younger children, with studies estimating a median age at diagnosis of 3-4 years  . The clinical presentation of choroid plexus tumors stems from the mechanical obstruction of cerebrospinal fluid (CSF) flow through the ventricular system and increased CSF production, eventually producing chronic raised intracranial pressure and hydrocephalus  . Nausea, vomiting, headaches, ataxia, nystagmus, dizziness, and diplopia are typical consequences of hydrocephalus and are highly indicative of a tumor originating from the fourth ventricle . On the other hand, papilledema, hemiparesis, seizures, and changes in the mental status are typically encountered when the tumor is situated in the lateral ventricle . An increased circumference of the head, bulging fontanelles, separated sutures, irritability, and a delayed development are findings that may be encountered in the first few years of life   . Development of choroid plexus tumors (both papillomas and carcinomas) is very rare in the adult population, but cases have been documented  . Benign choroid plexus tumors - papillomas, carry very high 5-year survival rates (reaching up to 100% in some studies) with an early recognition and appropriate therapy  , whereas carcinomas have a substantially worse prognosis (as low as 26% of patients survive 5 years after the diagnosis), particularly if the tumor is recognized late   .
In order to make a prompt diagnosis, it is necessary to perform a thorough clinical assessment comprised of a detailed patient history and a complete physical examination. Once clinical findings point to increased intracranial pressure or hydrocephalus, imaging studies should be immediately employed. Computed tomography (CT) and magnetic resonance imaging (MRI) are the two main studies used, each describing important tumor features . In the case of malignant choroid plexus tumor, CT will show a hypodense intraventricular mass that is lobulated, often containing calcifications that substantially enhance after contrast administration . On MRI, papillomas appear as isointense or hypointense intraventricular masses compared to the brain tissue, while carcinomas tend to be more heterogeneous due to the invasion of adjacent brain tissue and necrosis . Additional findings that point to carcinoma are hypointense or isointense T1-weighted studies and hyperintense T2-weighted studies . However, a definite distinction between the two types of choroid plexus tumors is made after a histopathological examination which examines the level of mitosis, growth pattern, and the degree of necrosis   . Expression of vimentin, S-100, and cytokeratin are well-documented in choroid plexus papilloma .