Pituitary adenoma producing amyloid-like substance.

Light and electron microscopical examination of a pituitary adenoma showed that the tumor was composed of prolactin cells that produced amyloid-like material. The findings have been interpreted in favor of the role of rough endoplasmic reticulum in amyloid fibril formation within the adenoma cells. Histochemical and fine structural data indicate that the material produced by this tumor resembles apudamyloid rather than immunoamyloid.