9-year-old male with pilomyxoid astrocytoma of fourth ventricle.
Findings: Well-defined solid space occupying lesion within fourth ventricle inseparable from its floor. It is hypointense on T1 (a), hyperintense on T2 (b) and FLAIR (c), without diffusion restriction (e), and shows internal patchy post contrast enhancement (f). It is not showing any focus of susceptibility on SWI sequence to suggest internal Hemorrhage (d). This lesion is causing significant proximal obstructive hydrocephalus and periventricular CSF seepage.
Figure 1: MRI Brain with contrast

9-year-old male with pilomyxoid astrocytoma of fourth ventricle.
Findings: (a) Monochromatic population of bipolar cells with predominant angiocentric arrangement and prominent myxoid background (hematoxylin and eosin X 20). (b) Diffuse, strong immunoreactivity for GFAP immunostain. These features are consistent with pilomyxoid astrocytoma.
Figure 2: Microscopic examination

22-year-old female with suprasellar pilocytic astrocytoma.
Findings:  Preoperative CT scan showing isodense non-enhancing lesion in suprasellar region resulting in obstructive hydrocephalus.
Figure 3: CT scan with contrast

22-year-old female with suprasellar pilocytic astrocytoma.
Findings:  Preoperative CT scan showing isodense non-enhancing lesion in suprasellar region resulting in obstructive hydrocephalus.
Figure 4: CT scan with contrast

22-year-old female with suprasellar pilocytic astrocytoma.
Findings:  Preoperative CT scan showing isodense non-enhancing lesion in suprasellar region resulting in obstructive hydrocephalus.
Figure 5: CT scan with contrast

22-year-old female with suprasellar pilocytic astrocytoma.
Findings:  Preoperative CT scan showing isodense non-enhancing lesion in suprasellar region resulting in obstructive hydrocephalus.
Figure 6: CT scan with contrast

22-year-old female with suprasellar pilocytic astrocytoma.
Findings:  Preoperative CT scan showing isodense non-enhancing lesion in suprasellar region resulting in obstructive hydrocephalus.
Figure 7: CT scan with contrast

22-year-old female with suprasellar pilocytic astrocytoma.
Findings:  Preoperative CT scan showing isodense non-enhancing lesion in suprasellar region resulting in obstructive hydrocephalus.
Figure 8: CT scan with contrast

22-year-old female with suprasellar pilocytic astrocytoma.
Findings:  Preoperative CT scan showing isodense non-enhancing lesion in suprasellar region resulting in obstructive hydrocephalus.
Figure 9: CT scan with contrast