case_images: PMC10927177_01
case_images: Preoperative images. Preoperative computed tomography (a) shows an isodense mass in the left cerebellar tonsil. In magnetic resonance imaging, the mass shows low intensity in (b) T1-weighted images and high intensity in (c) T2-weighted images. T2 hypertense cyst (d) is located in the cerebellar vermis. Post-contrast T1-imaging shows an enhanced mural nodule in the cyst (e, axial view, and f: sagittal view). The cerebral angiography (g) shows no tumor stains.
case_images: SNI-15-33-g001.jpg
case_images: PMC10927177_01_SNI-15-33-g001.jpg
case_images: F1
case_images: Computed tomography showed a heterogeneous cystic mass in the left cerebellum without calcification [Figure 1a]. MRI indicated a T1 hypointense and T2 hypertense mass in the left cerebellar tonsil and a T2 hypertense cyst in the cerebellar vermis [Figures 1b-d]. Post-contrast T1 imaging showed an enhanced mural nodule in the cyst [Figures 1e and f]. Cerebral angiography revealed no mass stain from vertebral arteries [Figure 1g].
case_images: Surgical view. The surgical view shows a grayish tumor (black asterisk) located in the cerebellar tonsil (red asterisk).
case_images: SNI-15-33-g002.jpg
case_images: PMC10927177_01_SNI-15-33-g002.jpg
case_images: F2
case_images: The tumor was located within the cerebellar tonsil and was well-circumscribed from the surrounding parenchyma [Figure 2].
case_images: Surgical specimens. Photomicrographs of the surgical specimen stained with hematoxylin and eosin show binuclear atypical ganglion-cell-like cells (a black arrow) and (a) proliferation of atypical glial cells showing mild pleomorphism between (b) hyalinized vessels, (c) eosinophilic granular bodies, and Rosenthal fibers. Immunohistochemical stains show that tumor cells are immunoreactive for (d) synaptophysin and (e) neurofilament protein.
case_images: SNI-15-33-g003.jpg
case_images: PMC10927177_01_SNI-15-33-g003.jpg
case_images: F3
case_images: Hematoxylin and eosin staining of the surgical specimen showed binuclear atypical ganglion-cell-like cells and proliferation of atypical glial cells showing mild pleomorphism between hyalinized vessels, eosinophilic granular bodies and Rosenthal fibers [Figures 3a-c]. Synaptophysin and neurofilament protein-positive ganglion cells were observed [Figures 3d and e].
case_images: Postoperative images. (a) Postoperative T2-weighted images and (b) contrast-enhanced T1-weighted images show that the mass is totally excised.
case_images: SNI-15-33-g004.jpg
case_images: PMC10927177_01_SNI-15-33-g004.jpg
case_images: F4
case_images: At the 1-year follow-up, postoperative MRI showed total tumor removal, and there has been no recurrence [Figures 4a and b].