PMC3513852_01
Initial MRI findings in a 17-year-old patient who presented with progressive headache and nausea. Axial T1-weighted (a) T2-weighted (b) contrast-enhanced T1-weighted (c) and sagittal T2-weighted (d) MR images revealed a multicystic lesion in the midbrain and thalamus causing aqueduct stenosis. A T2-weighted image (e) obtained after endoscopic ventriculocystostomy and third ventriculostomy showed a reduction in ventricular size, with no change in the multicystic lesion
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F1
Neurological examination showed papilledema, and MRI [Figure 1a-d] revealed hydrocephalus and a bilateral multicystic lesion in the midbrain and thalamus that caused aqueduct stenosis. PVS dilation. Postoperative MRI [Figure 1e] revealed a marked improvement in hydrocephalus, but no change was observed in the size or number of the multicystic lesion.
Increase in cyst number and size 14 years after initial surgery. T2-weighted (a) and sagittal T2-weighted (b) MR images revealed a multicystic lesion in the midbrain and thalamus that had increased in number and size, but no hydrocephalus was observed. Axial T2-weighted (c) and sagittal T2-weighted (d) MR images obtained after the second surgery showed a slight reduction in the size of the multicystic lesion
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F2
MRI [Figure 2a and b] revealed that a multicystic lesion in the midbrain and thalamus had increased in number and size compared with the initial examination at age 17, but hydrocephalus was not present. Postsurgical MRI [Figure 2c and d] revealed a slight reduction in the size of the multicystic lesion.
Endoscopic view of the third ventricle (a) showing the thin-walled cysts. After fenestration, an endoscopic view into the interior of a cyst (b) demonstrated perforating arteries ( ) surrounded by an enlarged perivascular space ( )
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F3
Thin-walled cysts were observed in the third ventricle [Figure 3a]. The interior of the cysts appeared to be traversed by small arteries that were surrounded by enlarged PVSs [Figure 3b].
Histological section of a biopsied cyst wall strained with hematoxylin and eosin (a) and immunostained for the astrocytic marker glial fibrillary acidic protein (GFAP) (b) or for the neuronal marker microtubule-associated protein (MAP2) (c) GFAP immunostaining revealed extensive gliosis in the cyst wall. Epithelial cells on the outer aspects appeared to be ependymal cells compressed by the multicystic lesion. No neurons were identified by MAP2 staining. Original magnification: x400
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F4
Histopathological staining for glial fibrillary acid protein (GFAP) [Figure 4a-c] demonstrated extensive gliosis in the cyst wall.
Axial T2-weighted (a) and sagittal T2-weighted (b) MR images obtained 6 months after the second surgery showing a slight reduction in the number and average size of the cysts
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F5
MRI, surgical, and histological findings, we diagnosed the patient with a multicystic lesion, which was caused by giant tumefactive PVSs. MRI performed at 6 months after surgery [Figure 5] showed a slight reduction in the number and average size of the cysts, and the patient remained free of symptoms.