case_images: PMC6744824_01
case_images: Magnetic resonance imaging from initial presentation with hydrocephalus (HCP). (a) T1-weighted image (T1WI) with contrast axial view. Demonstrates uniformly enhancing lesion within the posterior aspect of the third ventricle obstructing aqueduct. This results in triventricular HCP. (b) T1WI with contrast coronal views. Demonstrates uniformly enhancing mass within the cortical aspect of the third ventricle blocking the aqueduct. This results in triventricular HCP. No transependymal flow was noted on FLAIR sequence, suggesting HCP to be longstanding.
case_images: SNI-10-73-g001.jpg
case_images: PMC6744824_01_SNI-10-73-g001.jpg
case_images: F1
case_images: Magnetic resonance imaging (MRI) at the time revealed a small enhancing lesion in the posterior third ventricle at the cerebral aqueduct causing obstruction [Figure 1].
case_images: Last magnetic resonance imaging (MRI) before admission. (a) T1WI with contrast axial view (similar cut as initial MRI). Significant improvement in obstructive HCP following successful ETV. The uniformly enhancing mass within the third ventricle is stable in size compared to prior MRI. (b) T1WI with contrast coronal view (similar cut as initial MRI). The uniformly enhancing mass within the third ventricle appears to be stable in size, and spans almost the entire length of the third ventricle.
case_images: SNI-10-73-g002.jpg
case_images: PMC6744824_01_SNI-10-73-g002.jpg
case_images: F2
case_images: Three years after the initial presentation, the patient experienced acute onset of nausea and headache, and he was found to have new obstructive hydrocephalus secondary to IVH imaged on computed tomography head and MRI [Figures 2 and 3].
case_images: (a) CTH and magnetic resonance imaging during this admission. (a) Axial noncontrast head computed tomography (CT). IVH is noted within the third ventricle and aqueduct. Triventricular obstructive HCP is also noted. (b) Coronal non-contrast CTH. IVH is noted within the third ventricle which results in obstructive triventricular HCP. (c) T1WI with contrast axial view. IVH is noted within the third ventricle and occipital horns with resultant triventricular obstructive HCP. Contrast-enhancing lesion is noted within the anterior superior aspect. (d) T1WI with contrast coronal view. IVH is noted within the third ventricle with resultant triventricular obstructive HCP. The contrast-enhancing lesion is noted within the anterior superior aspect of the third ventricle.
case_images: SNI-10-73-g003.jpg
case_images: PMC6744824_01_SNI-10-73-g003.jpg
case_images: F3
case_images: Three years after the initial presentation, the patient experienced acute onset of nausea and headache, and he was found to have new obstructive hydrocephalus secondary to IVH imaged on computed tomography head and MRI [Figures 2 and 3].
case_images: Intraoperative pictures of right sided interhemispheric transcallosal approach to the third ventricular mass. (a) Zoomed out view of the left lateral ventricle with foramen of Monro at 12 o' clock, anterior septal vein at 3 o' clock, and choroid plexus at the center of the picture. (b) zoomed in view of the left lateral ventricle with better visualization of the foramen of Monro, anterior septal vein, and choroid plexus. The red/purplish tumor is starting to come into view within the foramen of Monro. (c) The third ventricular tumor is better seen within the foramen of Monro. It appeared to be more red and vascular, as supposed to the IVH clot which looked dark purple. (d) The tumor is better visualized at the 1 o'clock position. (e) The tumor being removed. After the tumor was removed, the third ventricle was explored, and the IVH clot was noted to be more posterior. It was then suctioned out.
case_images: SNI-10-73-g004.jpg
case_images: PMC6744824_01_SNI-10-73-g004.jpg
case_images: F4
case_images: An EVD was placed emergently, and the patient was taken to the operating room for an elective interhemispheric transcallosal approach to evacuate the IVH and definitively resect the posterior TVM with intraoperative image guidance [Figure 4].
case_images: Histopathology of resected tumor specimen concluded to be a WHO Grade II meningioma. (a) The neoplasm is composed of pleomorphic cells with irregular nuclei and prominent nucleoli. Hemosiderin pigment is present in the center of the field, indicating prior hemorrhage. Two mitoses (white arrows) are present in this high magnification photomicrograph. (H and E, x300). (b) The tumor does not have the morphology of a low-grade meningioma, but there is an attempt at whorl formation in the bottom left in this field. (H and E, x250). (c) The Ki67 (Mib-1) nuclear labeling index is significantly higher that would be expected in low grade meningiomas. (Ki67 immunohistochemistry, x125).
case_images: SNI-10-73-g005.jpg
case_images: PMC6744824_01_SNI-10-73-g005.jpg
case_images: F5
case_images: Final pathology of the mass revealed it to be the WHO Grade II meningioma [Figure 5].