case_images: PMC3307247_01
case_images: (a, b) Emergency brain CT displaying a left-sided putaminal hematoma of 9 cm3 and a rounded hyperdense lesion of 2.5 cm in its major diameter, located at the anterior third ventricle, which causes acute biventricular hydrocephalus. There are signs of intraventricular bleeding in contact with the outer border of the lesion at the left foramen of Monro. (c) Brain T1-weighted Gadolinium-enhanced MRI. This parasagittal slice shows a homogeneous hyperintense rounded lesion in the anterosuperior part of the third ventricle. (d) Postoperative mid-sagittal slice of a T1-weighted MRI showing no signs of residual tumor at the third ventricular chamber. The inset in the upper right corner corresponds to a right parasagittal slice displaying the small callosal section performed during the surgical approach
case_images: SNI-3-24-g001.jpg
case_images: PMC3307247_01_SNI-3-24-g001.jpg
case_images: F1
case_images: Acute obstructive hydrocephalus due to a rounded hyperdense mass within the third ventricle was revealed on the emergency brain computed tomography (CT), in addition to a moderate size acute hematoma in the left basal ganglia [Figure 1a and b]. After clinically stabilizing the patient, a presumed diagnosis of a colloid cyst within the third ventricle was made by magnetic resonance imaging (MRI) [Figure 1c]. Follow-up MRI study confirmed total resection of the lesion [Figure 1d].
case_images: Colloid cyst showing a lining of columnar epithelium and acellular debris in the cavity, with signs of vascular congestion and recent hemorrhage within its wall (H and E, x100). The high power inset shows ciliated columnar cells and mucin-containing cells (PAS-diastase, x630)
case_images: SNI-3-24-g002.jpg
case_images: PMC3307247_01_SNI-3-24-g002.jpg
case_images: F2
case_images: Pathological analysis of the lesion confirmed the diagnosis of a colloid cyst with vascular congestion and foci of acute bleeding within its wall [Figure 2].