Immunohistological study of Crooke's cells.

ABSTRACT

By immunohistochemical methods, 28 postmortem pituitary glands with unequivocal Crooke's hyaline change were examined to identify the hyaline material. Crooke's hyaline was positive for 55-57 kilodalton (KD) cytokeratin (CK) but negative for 68 KD CK, vimentin, desmin, neurofilament and glial fibrillary acidic protein. Involucrin, a new marker for keratinocyte differentiation, could also not be demonstrated. It was concluded that Crooke's hyaline was an abnormally accumulated CK which is a normal constituent of the ACTH cell.