Endoscopy-verified occult subependymal dissemination of glioblastoma and brain metastasis undetected by MRI: prognostic significance

Figures & data

Figure 1 Contrast-enhanced, axial, T1-weighted magnetic resonance images of the tumor.

Notes: Initial images showing a large, heterogeneously enhancing tumor in the right temporal lobe, extending to the choroid plexus of the right lateral ventricle and to the temporal horn, infiltrating the hippocampus (A). Images at 6 months after the first operation, documenting a gross total resection of the tumor without evidence of recurrences (B).

Figure 2 The patient’s third ventricle nodular lesion.

Notes: Contrast-enhanced magnetic resonance images at the 11-month follow-up revealing the onset of an apparently solitary nodular lesion in the third ventricle, while the operative site was still disease-free (A). Postoperative computed tomography scan showing the resection of the nodular lesion in the third ventricle without complications (B).

Figure 3 Close-up endoscopic third ventricle views.

Notes: The nodule inside the third ventricle, just beneath the opened ependymal layer (A). Endoscopic view after tumor removal with the origin of the sylvian aqueduct (B). The floor of the third ventricle detecting a diffuse tumor infiltration composed of small adjacent nodules lying beneath the ependyma, unidentified by MRI and PET scan (C and D).

Figure 4 H and E glioblastoma multiforme, World Health Organization grade IV, with evidence of nuclear pleomorphism, mitotic activity, endothelial hyperplasia, and areas of palisading necrosis.

Figure 5 Preoperative, contrast-enhanced, axial, T1-weighted magnetic resonance images.

*The left ventricle looked normal.

Notes: Multiple heterogeneously enhanced lesions, proximal to the choroid plexus of the right lateral ventricle, with mild associated perilesional edema and right ventricular enlargement due to occlusion of the foramen of Monro* (A and D). Contrast-enhanced, axial, T1-weighted magnetic resonance image at the 6-month follow-up showing the resolution of the obstructive hydrocephalus (B). At this time, MRI also documented the contralateral tumor infiltration along the anterior commissure (E), not detected at the preoperative MRI (D), although it was evident during the endoscopic procedure. Contrast-enhanced, axial, T1-weighted MR image at the 18-month follow-up showing a massive subependymal tumor infiltration of the left lateral and third ventricles with growth and diffusion of the tumor in the right lateral ventricle (C and F).
Abbreviation: MRI, magnetic resonance imaging.

Figure 6 Diffuse yellowish coloration of the walls of the right lateral ventricle discovered during neuroendoscopic examination, with clusters of neoplastic cells embedding the choroid plexus and a thin sheet of tumor cells forming small nodules in the subependymal region (A–C). Endoscopic view of the septostomy with a contralateral apparently normal ependymal layer and choroid plexus (D and E). Close-up view of an initial, contralateral tumor infiltration evident through the fibers of the subependymal layer, situated along the anterior commissure (F). This finding was undetected by preoperative magnetic resonance imaging (see Figure 5D).

Figure 7 H&E staining of neoplastic epithelial tubules and glands infiltrating the brain parenchyma.

Notes: The cells show aspects of mucosecretion (A). Immunohistochemistry was positive for cytokeratin 20 (B) and CEA (C).
Abbreviations: CEA, carcinoembryonic antigen; H&E, hematoxiline and eosin.