Contributions of immunohistochemistry and in situ hybridization to the functional analysis of pituitary adenomas

Immunohistochemistry (IHC) and recently in situ hybridization (ISH) have el ucidated various aspects of human pituitary adenomas, i.e., functional diff erentiation and classification, transcription factors and mechanism of horm one production, regulation of hormone secretion, and processing of prohormo nes. Recently, the use of tyramide (catalyzed signal amplification; TSA or CSA) and RT-PCR has been effective for detection of trivial amount of prote ins (peptides) and mRNA, respectively. Immunomolecular histochemistry is ex pected to further clarify the function and biology of human pituitary adeno mas.