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Microbes & Immunity Characterizing low-grade CNS tumors

3. Results Dystrophic microcalcifications were most abundant
within the lobules of ependymoma, moderately dispersed
3.1. Histopathological findings, MRI metadata, and in astrocytoma, and sparse in meningioma. Each tumor
evaluation of glial/non-glial nature
type exhibited a distinct histoarchitectural profile. The
Histopathological analysis at ×100 and ×400 magnifications progressive increase in nuclear atypia and vascular
revealed distinct architectural features for each tumor type. proliferation from meningioma to ependymoma to
Ependymoma exhibited lobulated, island-like patterns astrocytoma suggests an escalating degree of biological
with hyalinized fibrovascular cores and characteristic aggressiveness, even within low-grade classifications.
perivascular pseudorosettes (Figures 1B and 1C).
Meningioma demonstrated classic “whorling” formations MRI of myxopapillary spinal ependymoma (Figure 1A)
resulting from interlacing fascicles of fibroblastic origin revealed a heterogeneous lesion extending from L1 to
(Figure 1F and 1G). In diffuse fibrillary astrocytoma, we L5, with a loss of normal lumbar curvature. The lesion
noted increased glial cell density and a prominent fibrillary appeared iso- to hyperintense on T2-weighted images.
network (Figure 1J and 1K). Among the astrocytoma MRS demonstrated a markedly elevated choline peak
specimens, nuclear atypia and pleomorphism – hallmarks and a significantly reduced NAA peak. In meningioma
of malignancy – were most pronounced. Vascular (Figure 1E), imaging revealed a large extra-axial mass in the
proliferation was most extensive in astrocytoma, followed midline basifrontal region, showing intense post-contrast
by lobular-specific vascular islands in ependymoma and enhancement. The mass appeared iso- to hypointense on T1
moderate, sprouting vasculature in meningioma. and iso- to mildly hyperintense on T2-weighted sequences,

A B C D

E F G H

I J K L

Figure 1. Radiological, histopathological, and immunofluorescence analysis of tumor samples. Low-grade spinal myxopapillary ependymoma: T1- and
T2-weighted magnetic resonance (MR) images of (A); Hematoxylin and eosin (H&E)-stained histopathological sections at ×100 (scale bar: 100 µm) and
×400 (scale bar: 50 µm) magnification (B and C); Glial fibrillary acidic protein (GFAP) immunofluorescence (D), with glial cells indicated by orange arrows;
Low-grade fibroblastic meningioma: MR images (E); H&E-stained sections at ×100 (scale bar: 100 µm) and ×400 (scale bar: 50 µm) magnification (F and
G); GFAP immunofluorescence, with glial cells indicated by orange arrows (H); Low-grade diffuse astrocytoma: MR images (I); H&E-stained sections at
×100 (scale bar: 100 µm) and ×400 (scale bar: 50 µm) magnification (J and K); GFAP immunofluorescence, with glial cells indicated by orange arrows (L).

Volume 2 Issue 3 (2025) 134 doi: 10.36922/MI025190040