Lateral ventricle tumor diagnosis
Although these neoplasms are easily detected with computed tomography (CT) and magnetic resonance imaging (MRI), both techniques are relatively unspecific in identifying the type of tumor. However, few imaging patterns are specific to a particular pathological process and useful conclusions can be made from the morphological appearance of the lesion, its location, and enhancement pattern. The aim of this article was to review and illustrate the CT and MRI findings of a wide spectrum of tumors of the lateral ventricle. We reviewed choroid plexus tumors, meningioma, subependymal giant cell astrocytoma, central neurocytoma, and less frequent lesions such as lymphoma and metastases 1).
For the radiological analyses, the lateral ventricle tumors are classified into two groups, as follows: 1. Intraventricular tumors arise in the projection of the choroid plexus, the tela chorioidea and the ependyma and grow in the lateral ventricle. 2. Paraventricular tumors arise from the wall of the neuroglia that not only bulges into the ventricle but in addition infiltrates the substance of the surrounding brain. Following conclusions are obtained. (1) Unilateral hydrocephalus, which is shown clearly by vascular displacements in subependymal veins, is demonstrated in both tumor groups. (2) There are different findings on the feeding arteries, the draining veins, and the tumor stains between the two tumor groups. (3) In the intraventricular tumor groups, the anterior choroidal artery supplying the tumor is its plex segments and atrial segments. (4) On the other hand, in the paraventricular tumors group, the anterior choroidal artery supplying the tumor is its superior penetrating branch to the cerebral parenchyma. (5) Cerebral angiograms can reveal definite signs of the intraventricular mass, but it is sometimes difficult to evaluate whether its space-occupying lesions infiltrate the cerebral substance below the wall of the lateral ventricle, or not. (6) CT scan is a useful neuroradiological method in the differential diagnosis between two tumor groups, and a CT scan provides an anatomical diagnosis rather than a histological one. (7) The accurate diagnosis of the tumors of the lateral ventricle can be demonstrated by both cerebral angiograms and CT scan 2).
CT
Unilateral dilatation of the lateral ventricle is a rare condition. The most common causes are tumors of the lateral ventricles or in the area of the third ventricle.
Hyperdense solid mass in the midline, supratentorial, located in both lateral ventricles.
MRI
Intraventricular tumor with aggressive characteristics with signs of subependymal spread/drop metastasis. To assess, among others, Choroid plexus tumor, ependymoma, metastasis…
The intraventricular lesion up to 54x34x30mm that extends through both lateral ventricles crossing the midline; more on the left where it makes extensive contact with the choroid plexus. It appears minimally hyperintense on T2 and minimally hypointense on T1 with diffusion restriction and very low signal on ADC associated with striking and homogeneous enhancement without intralesional bleeding or calcification. Shows signs of the infiltration of the adjacent corpus callosum with edema/increased signal in both corona radiates A 4mm enhancement focus was associated in the most medial area of the left caudate and periventricular adjacent to the posterior horn of the ipsilateral ventricle as well as a 9mm enhancement in the IV ventricle and on the left edge of the mime; impressing this affectation of subependymal dissemination, drop metastasis….. Secondary hydrocephalus with an Evans index of 0.31, but with increased diameter in the temporal and occipital horns.