Immunocytochemistry of folliculo-stellate cells of normal and neoplastic human pituitary gland.

Five normal human pituitaries and 20 pituitary neoplasms were investigated by immunocytochemical methods. Glial fibrillary acidic protein and S100 have been shown in the anterior lobe of the pituitary. Both these markers were present in the folliculo-stellate cell. Evidence is presented for the presence of a transitional folliculo-stellate cell which is immunoreactive for S100. The role of the folliculo-stellate cell is discussed.