An immunoperoxidase study of a human pituitary adenoma associated with Cushing's syndrome

Immunohistological studies for gastrointestinal and other hormones in acth-secreting adenomas

Eighty-nine ACTH-secreting pituitary adenomas from patients with Cushing's disease or Nelson's syndrome were investigated by immunohistochemical methods for their content of gastrin, cholecystokinin (CCK), vasoactive intestinal peptide (VIP), bombesin, substance P, and ubiquitin as a marker for intercellular fibrils and hyalin and D11 as a marker for adrenocortical tissue. In contrast to in vitro studies reported in the relevant literature, we did not find significantly positive percentages (more than 10% of adenoma cells) for gastrin and CCK. VIP and bombesin were demonstrated in one adenoma. Among the adenomas examined, ubiquitin was found in 15% and D11 in 75%. ACTH was present in 99%, pro-γ-MSH in 21 %, β-endorphin in 13%, enkephalin in 4%, and α-subunit in 11.5%. The significance of the findings is discussed.

Ultrastructural diagnosis of human pituitary adenomas

Electron microscopy, which has been instrumental in the characterization of normal pituitary cell types, has also played a crucial role in the morphologic classification of pituitary adenomas arising in the presently known 5 cell types, and in the recognition of 3 adenoma types with yet undisclosed cell derivation. This review deals with the application of electron microscopy for study of pituitary adenomas in order to provide specific pathological diagnosis and aid the clinician in selecting appropriate postoperative treatment. In addition to the ultrastructural appearance and diagnostic features of 15 adenoma types, the morphology of hyperplastic proliferations and that of known normal counterparts of various adenoma types are also discussed. Specific morphologic diagnosis of pituitary lesions is important not only for adequate postoperative management of patient, but is also a prerequisite for study of the natural history and biological behaviour of various adenoma types.