Background: Intraventricular manifestation of a hamartoma is an unusual clinical entity.
Case description: A 12-year-old girl was admitted with complaints of dizziness and head heaviness. Computed tomography and T1-weighted magnetic resonance imaging (MRI) demonstrated an isodensity or isointensity mass lesion with cystic component in the right lateral ventricle, which showed relatively high signal intensity on T2-weighted MRI and lacked contrast enhancement. Histopathologic examination on the surgically removed specimens using glial fibrillary acidic protein, Klüver-Barrera, Bodian stainings, bromouridine labeling index, and MIB-1 immunohistochemical staining confirmed that the tumor had glial and neuronal components and low proliferative potentiality.
Conclusion: This case is the first report of intraventricular hamartoma, although some reports on intracranial hamartoma located in areas other than the hypothalamus have been published. The radiologic findings, including relatively high signal intensity on T2-weighted MRI and absence of contrast enhancement, may be suggestive of the diagnosis of intraventricular hamartoma; however, the specific stainings for glial and neuronal cells and proliferative evaluation are essential to the precise diagnosis of hamartoma. Clinical manifestation of hamartoma in the ventricular system, though rare, should be kept in mind.