PMC8942190_01
Magnetic resonance imaging (MRI) findings. Initial fluid-attenuated inversion recovery MRI showing an intraventricular tumor (a). Initial T2-star weighted MRI (T2*WI) also revealed a tiny low-intensity spot (arrow), suggesting intratumoral hemorrhage 7 years before surgery (b). Note that 5 years before surgery, this signal change was localized within the tumor and not on the brain surface (c). Low intensity suggesting intratumoral hemorrhage and superficial siderosis on the brain surface (arrowhead) is demonstrated on T2*WI 3 years before surgery and ventricular enlargement progresses (d), and is exacerbated immediately before surgery (e). Hemosiderin deposition and hydrocephalus persisted even after tumor removal (f).
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F1
A 78-year-old man with an intraventricular tumor diagnosed 7 years before had been suffering from gait disturbance for 2 years [Figure 1, 1a and 1b]. Monro, but ventricular enlargement had been observed 3 years before and had worsened, reaching an Evans index of 0.36 [Figure 1d]. Magnetic resonance imaging (MRI) T2*WI captured small intratumoral hemorrhages from the beginning of the follow-up [Figure 1a, b and c]. Three years before, at the same time as the onset of ventricular enlargement, low intensity of the whole tumor and cerebral surface was observed on T2*WI [Figure 1d]. Subsequent follow-up revealed that this hemosiderin deposition had spread to the brain stem and cerebellar surface, and the ventricles had further expanded [Figure 1e]. During the postoperative course, MRI revealed total tumor removal and no postoperative complications [Figure 1f].
Cerebrospinal fluid (CSF) testing before and after surgery. (a) CSF before surgery showing xanthochromia. (b) CSF after surgery showing clear crystals.
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F2
On the other hand, CSF analysis demonstrated xanthochromia, a white blood cell (WBC) count of 154/mul (normal range 0-15/muL), and protein level of 596 mg/dL (normal range 10-40 mg/dL) [Figure 2 and 2a]. Postoperative CSF was drastically improved, being crystal clear, WBC count of 1/mul, and protein level of 88 mg/dL [Figure 2b].
Intraoperative photographs of the left lateral ventricle. (a) Black asterisk showing the ventricular wall is colored yellowish-brown, suggesting deposition of hemosiderin on the ependyma. (b) The tumor surface turns a mixture of yellow and red, suggesting the presence of hemorrhage at different times.
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F3
Visual inspection revealed that the ventricular wall turned yellowish-brown, suggesting deposition of hemosiderin on the ependyma [Figure 3a]. The tumor surface was a mixture of yellow and red, suggesting the presence of hemorrhage at different times [Figure 3b].
(a) Low magnification and (b) high magnification: hematoxylin and eosin staining. Clusters of oval-shaped cells and isomorphic nuclei are embedded in a fine fibrillary back ground. Many microcystic formations and microbleeding changes were also seen in the tumor. (c) Immunohistochemical staining revealing a positive reaction for glial fibrillary acidic protein. The pathological findings of a-c are consistent with those of subependymoma. (d) Elastica van Gieson staining revealed a positive reaction for collagen type IV on the vessel walls, which suggests that the vessel walls in the tumor are normal.
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F4
Although the tumor surface color suggested that multiple hemorrhages in different phases and slight microbleeding changes were observed in the tumor, Elastica van Gieson staining did not reveal any significant disruption of the tumor blood vessels [Figure 4].