Figure 5c. Germinoma of the pineal gland in an 11-month-old boy with sporadic vomiting. Because no abdominal cause was found, the brain was examined. (a) Nonenhanced computed tomographic (CT) scan shows a partly calcified mass in the pineal region (arrow). (b, c) Sagittal T2-weighted (b) and contrast-enhanced T1-weighted (c) MR images show that the mass (black arrows in b) is solid with small cysts and marked enhancement. The tumor extends upward, compressing and displacing the internal cerebral vein (white arrows in b). (d) Photomicrograph (original magnification, x400; H-E stain) shows that the tumor is composed of large, rounded cells with clear cytoplasm.