[Immunohistochemical and ultrastructural study of plurihormonal pituitary adenomas]

38 cases of plurihormornal pituitary adenomas containing growth hormone were detected by PAP technique for GH, PRL, ACTH, TSH and GnH. Plurihormonal pituitary adenomas were classified according to their hormonal content and pattern of hormonal combinations. Under the transmission electron microscopy, the plurihormonal pituitary adenomas might be monomorphous or multimorphous, thus, one morphologic cell type could elaborate several hormones. Using immunoelectron microscopical colloidal gold double labelling technique, we found 3 kinds of hormonal distribution in plurihormonal pituitary adenomas: different cells containing different hormones; one cell with plural hormones, even one secretory granule with two hormones; combination the former two. Even in the normal pituitary anterior lobe, we found there were cells secreting one type of hormone and also cells secreting plural hormones. Plurihormonal pituitary adenomas might derive from multiple cell type, from one cell type, or from both cell containing one type of hormone and cell containing plural hormones.