[Intraventricular cavernoma in the foramen of Monro: particularities due to its atypical location].

Although cavernomas are relatively common vascular malformations in the central nervous system, they are rarely located in the ventricles and are even more rarely located in the region of the foramen of Monro. This atypical location results in a series of differential clinical and radiological characteristics that can make the diagnosis of these lesions extremely difficult and lead to inefficacious procedures like radiotherapy or a neuroendoscopic surgical approach or even to procedures that endanger the patient like stereotactic biopsy. We present a case of intraventricular cavernoma in the region of the foramen of Monro with the aim of illustrating the difficulties involved in the diagnosis of this rare lesion.