PMC6666353_01
MRI images (a) Axial T1WI shows heterogeneous signal intensity tumor in the right side of the posterior fossa, mainly iso-to slightly low signal intensity, with multiple round-like low signal intensity regions. The masses have well-defined margins, the right cerebellar hemisphere and vermis are involved, the fourth ventricle and brain stem are compressed and deformed. (b) Axial T2WI shows that the tumor appears as iso-to slightly high signal intensity, with multiple round-like high signal intensity regions. Contrast enhanced MRI. (c) Axial contrast enhanced MRI shows that the mass had obvious heterogeneous enhancement with peritumoral edema and non-enhancement regions of multiple small round cystic lesions and necrosis. (d) Sagittal enhanced image shows that the fourth ventricle was not clear and the contours of enhanced cauliflower-like masses. (e) Axial enhanced image of enhanced FLAIR sequence shows multiple non-enhanced cystic lesions and necrosis more clearly
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F1
Magnetic Resonance Imaging (MRI): Non-enhancement MRI (Figure 1a, b) showed a heterogeneous signal intensity mass in the right side of the posterior fossa. Contrast-enhanced MRI scan (Figure 1c-e): The mass showed obvious heterogeneous enhancement, with multiple cystic regions.
Microscopic examinations of the tumor show many primitive neural tube, choroidea, squamous epithelium, appendix organ of skin, cartilage, bone, columnar epithelium, and muscle tissues
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F2
Immature teratoma [World Health Organization (WHO) grade III, posterior fossa], contained multiple primitive neural tubes, choroidea, squamous epithelium, appendix organs of skin, cartilage, bone, columnar epithelium, and muscle tissues (Figure 2). Immunohistochemistry: CK (+), EMA (+), 10% Ki67 (+), Syn (+), NF (+), GFAP (+), sporadic LCA (+), some desmin (+).