case_images: PMC6744778_01
case_images: T1-weighted image (WI) (a) shows the 4-cm tumor in the left cerebellum with hypointense signal. T2WI (b) shows the tumor with hyperintense signal. Axial (c) and coronal (d) images showed the tumor after application of contrast enhancement.
case_images: SNI-10-74-g001.jpg
case_images: PMC6744778_01_SNI-10-74-g001.jpg
case_images: F1
case_images: MRI revealed that the tumor was iso-to-hyperintense on T1-weighted image (T1WI) and hyperintense on T2WI and demonstrated strong contrast enhancement after gadolinium injection [Figure 1].
case_images: Postsurgical contrast T1-weighted magnetic resonance-images show complete resection of the tumor. (non-contrast T1-weighted image [WI] (a), T2WI (b), contrast T1WI (c), and diffusion- WI (d)).
case_images: SNI-10-74-g002.jpg
case_images: PMC6744778_01_SNI-10-74-g002.jpg
case_images: F2
case_images: Postoperative MRI (within 24 h) and contrast MRI (within 72 h) revealed complete resection of the tumor [Figure 2].
case_images: Hematoxylin and eosin (H and E) staining (a) low-power field, (b) high-power field) showed a proliferation of spindle-to-polygonal-shaped cells with irregular nuclei and eosinophilic cytoplasm arranged in a sheet-like pattern, accompanied by chronic inflammatory infiltration and hemangiopericytomas Staghorn-like branching vessels. Immunochemical staining for p53 marker was positive (c).
case_images: SNI-10-74-g003.jpg
case_images: PMC6744778_01_SNI-10-74-g003.jpg
case_images: F3
case_images: Histopathological analysis showed a proliferation of spindle-to-polygonal-shaped tumor cells with enlarged irregular nuclei and eosinophilic cytoplasm arranged in sheet-like patterns, accompanied by chronic inflammatory infiltration and hemangiopericytomas Staghorn-type branching vessels [Figure 3a and b]. Immunohistochemical panel demonstrated that tumor cells were positive for p53 [Figure 3c] and p16, focally positive for cytokeratin AE1/AE3 CAM5.3, alpha-smooth muscle actin, desmin, and muscle-specific actin (HHF35), but negative for multiple other markers such as cytokeratin CK5/6, CK903, CK14, p40, EMA, GFAP, Oligo-2, IDH-1, ERG, STAT6, and GRIA2.