PMC9479536_01
T2 (a), Post Contrast T1 (b), T1 (c), Post Contrast T1 (d), DW (e), ADC (f) images show an abnormal signal intensity lesion which is noted at the pre-Meckel cave segment of the right trigeminal nerve. It is iso to hypo intense on T1-WI and hyperintense on T2-WI with no post contrast enhancement or diffusion restriction.
SNI-13-365-g001.jpg
PMC9479536_01_SNI-13-365-g001.jpg
F1
Figure 1a-f represent the MR images signifying an abnormal signal intensity lesion at the pre-Meckel cave segment of the right trigeminal nerve, which is iso- to hypointense on T1-WI and hyperintense on T2-WI with no post contrast enhancement or diffusion restriction.
Image shows monomorphic tumor cells with round to oval nuclei forming perivascular pseudorosettes. There is no high cellularity, high mitotic activity, nor microvascular proliferation.
SNI-13-365-g002.jpg
PMC9479536_01_SNI-13-365-g002.jpg
F2
Histopathology sections of the lesion revealed tumor cells arranged predominantly around central blood vessels forming perivascular pseudorosettes [Figure 2].
Calcifications are noted in this image. The image also shows monomorphic tumor cells with round to oval nuclei forming perivascular pseudorosettes. There is no high cellularity, high mitotic activity, nor microvascular proliferation.
SNI-13-365-g003.jpg
PMC9479536_01_SNI-13-365-g003.jpg
F3
Scattered calcifications were also present [Figure 3].
(a,b) GFAP immunostain shows positive staining in tumor cells with stronger expression in perivascular tumor cells. Olig2 immunostain is negative.
SNI-13-365-g004.jpg
PMC9479536_01_SNI-13-365-g004.jpg
F4
Immunohistochemical stains were positive for glial fibrillary acidic protein, whereas Olig2 immunostain was negative [Figure 4a and b].