ABSTRACT
Intracranial hemangiopericytomas [HPCs] are rare central nervous system tumors arising from Zimmermann pericytes or mesenchymal cells. It is often difficult to distinguish these tumors from meningiomas based on clinical features and radiological findings. HPCs have been clinically detected in many of the intracranial compartments; here, we present a case with presumed meningioma that was adjacent to the right lateral ventricle and was confirmed by histopathology analysis. A 22-year-old man was referred to our hospital with a slowly expanding, painless mass adjacent to the right ventricle that he had first noticed by accident seven months before. Magnetic resonance imaging demonstrated the presence of homogeneously enhancing mass adjacent to the right lateral ventricle, which was suggestive of a meningioma. The tumor was definitively diagnosed as an intracranial HPC by pathological examination. It is imperative that the surgeon consider this rare diagnosis when evaluating patients with lesions regarded as extracerebral tumors.