Thyroid stimulating and gonadotrophic hormones in pituitary adenomas without clinical or serological abnormality

Forty-three chromophobe adenomas have been examined immunocytochemically for their hormonal content. Twelve cases with full pre-operative normal serum hormonal levels were found to have many positive cells within the tumour for thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH) and luteinizing hormone (LH). The specificity of the immunoreactive product within the tissue was checked by immunoabsorption. It is suggested that a non-secreted biologically inactive glycoprotein hormone is produced by tumour clones.