Administration of 2-Br- alpha-ergocryptine (bromocriptine = CB-154) in combination with an estrogen-receptor blocking agent tamoxifen were performed in two patients with prolactinoma and non-functioning adenoma, respectively. Case 1 was a 50-year-old male with hyperprolactinemia, impaired pituitary function and visual disorders, in whom a large invasive sellar mass lesion was disclosed by CT scans, which extended supra- and parasellarly and extracranially into paranasal sinuses and pterygopalatine fossa on the left side. As the effect of bromocriptine therapy was partial in tumor size reduction and decrease of serum PRL level and it could not be gained further improvement except for the well recovered visual acuity, tamoxifen was used together with bromocriptine resulting further reduction of tumor size and normalization of serum PRL level. Unexpectedly the medication was ceased during and after a couple of bypass surgery for angina pectoris, and it was followed by elevation of serum PRL level and regrowth of the sellar tumor as well as impairment of vision. By tamoxifen therapy the visual acuity showed some improvement, but the serum PRL level and the tumor size remained as before. Then the combination therapy with bromocriptine and tamoxifen was started again. Case 2 was a 38-year-old female with three children, who had secondary amenorrhea, galactorrhea, borderline level of serum PRL with impaired pituitary function and visual disorders. Under the diagnosis of a non-functioning pituitary adenoma with supra-sellar extension, a craniotomy was done and intracapsular partial removal of the tumor was made, revealing a chromophobe adenoma in light microscopy and undifferentiated cell adenoma in electron-micrographs.(ABSTRACT TRUNCATED AT 250 WORDS)