Some new observations in an intracranial germinoma.

A case of an intracranial germinoma from the suprasellar region of a 9-year-old girl was examined in the electron microscope. The tumor consists, for the most part, of both large polygonal and small lymphocyte-like elements. Annulate lamellae are common in the epithelial cells. The small blood vessels are fenestrated, and the endothelial cells contain tubular bodies, membrane-bounded vacuoles containing dense fluid and occasional tubules, arrays of tubules within the nuclear envelope and rough endoplasmic reticulum, and a markedly irregular luminal surface. Dense, lamellated structures are present in the widened, collagen-containing perivascular spaces.