Third ventricular choroid plexus arteriovenous malformation simulating a colloid cyst. Case report

Area of Science:

• Neurology
• Neurosurgery
• Radiology

Background:

• Arteriovenous malformations (AVMs) are abnormal tangles of blood vessels.
• Cystic encapsulated AVMs in the third ventricle are exceptionally rare.
• Accurate diagnosis is crucial for appropriate management.

Observation:

• A case presented with a lesion in the third ventricle.
• Computerized tomography (CT) scan suggested a colloid cyst due to location.
• The lesion showed atypical non-homogeneity before and after contrast infusion.

Findings:

• The CT scan's increased density on unenhanced scans was attributed to hemosiderin pigment.
• Hemosiderin resulted from prior hemorrhage within the AVM's capsule wall.
• Histological examination provided the definitive diagnosis of cystic encapsulated arteriovenous malformation.

Implications:

• This case underscores the importance of considering AVMs in the differential diagnosis of third ventricular lesions.
• Atypical imaging findings on CT should prompt further investigation.
• Histopathology remains the gold standard for diagnosing complex neurovascular lesions.