case_images: PMC11225526_01
case_images: Preoperative magnetic resonance imaging (MRI). Axial MRI post gad showing the cystic lesion with enhancing mural nodule (yellow arrow), and enhancement of the cystic wall (red arrow).
case_images: SNI-15-203-g001.jpg
case_images: PMC11225526_01_SNI-15-203-g001.jpg
case_images: F1
case_images: Initial investigations included computed tomography (CT) and magnetic resonance imaging (MRI) of the head, which revealed a cystic mass of the right cerebellar hemisphere measuring 4.1 x 3.2 x 3.2 cm [Figure 1]. Mitotic figures were scarce, and MIB-1/Ki67 was estimated at 5%.
case_images: (a) Low magnification view of the tumor with a thrombosed blood vessel; (b) higher magnification showing glial cells with piloid processes; (c) example of microvascular proliferation; (d) example of eosinophilic granular body (arrow); (e) glial fibrillary acidic protein (GFAP) immunohistochemistry showing diffuse immunoreactivity; and (f) low Ki67/MIB-1 proliferative index.
case_images: SNI-15-203-g002.jpg
case_images: PMC11225526_01_SNI-15-203-g002.jpg
case_images: F2
case_images: Mitotic figures were scarce, and MIB-1/Ki67 was estimated at 5%. In light of these findings, the tumor was histologically felt to be consistent with diffuse astrocytoma with high-grade features, as shown in Figure 2.
case_images: Postoperative magnetic resonance imaging four months after the first surgery showing a small infiltrative residual tumor (red arrow).
case_images: SNI-15-203-g003.jpg
case_images: PMC11225526_01_SNI-15-203-g003.jpg
case_images: F3
case_images: Mitotic figures were scarce, and MIB-1/Ki67 was estimated at 5%. A postoperative MRI done four months after surgery showed a small infiltrative residual tumor behaving like a diffuse glioma [Figure 3].
case_images: Eleven months after the first surgery, the patient presented with tumor recurrence. (a) Two lesions, one in the right cerebellar hemisphere, which is consistent with the location of the original tumor. Another lesion is seen centered in the fourth ventricle, likely arising from the residual tumor infiltrating the ventricular wall; (b) axial flair magnetic resonance imaging shows a portion of the tumor arising from the right lateral aspect of the fourth ventricular wall.
case_images: SNI-15-203-g004.jpg
case_images: PMC11225526_01_SNI-15-203-g004.jpg
case_images: F4
case_images: Mitotic figures were scarce, and MIB-1/Ki67 was estimated at 5%. In addition, there was a 1.6 x 1.4 cm lesion in the right cerebellar peduncle with an enhancing cystic component in the 4th ventricle [Figure 4].
case_images: Neuropathological findings from the second tumor (a) piloid cells with fibrillary cytoplasm; (b) microvascular proliferation; (c) mitotic activity (arrows); and (d) Ki67/MIB-1 proliferative index estimated to reach 25%.
case_images: SNI-15-203-g005.jpg
case_images: PMC11225526_01_SNI-15-203-g005.jpg
case_images: F5
case_images: Mitotic figures were scarce, and MIB-1/Ki67 was estimated at 5%. MIB-1/Ki67 proliferative index was also greater at 25% [Figure 5].