Reduction of pituitary-tumour size in patients with prolactinomas and acromegaly treated with bromocriptine with or without radiotherapy.

69 patients with prolactin-secreting or growth-hormone-secreting pituitary tumours were treated with bromocriptine with or without pituitary irradiation and followed up for 6 months to 6 1/2 years. Of 26 patients with prolactinomas, 11 had external pituitary irradiation in addition to bromocriptine. There was evidence of shrinkage of the pituitary tumour (either a reduction in fossa size or loss of visual-field defects) in 6 of these patients (23%), 3 of whom had been treated with bromocriptine alone. Of 43 acromegalic patients, 30 received external pituitary irradiation. 8 (19%) showed evidence of shrinkage of the pituitary tumour, including 2 who had received no radiotherapy. 1 patient treated with bromocriptine alone showed striking reduction in the size of his suprasellar extension, as assessed by serial computed-tomography scans over 11 months. At the same time his visual-field defects resolved and his deficient corticotrophin and thyrotrophin reserves returned to normal. Bromocriptine can reduce the size of both prolactin-secreting and growth-hormone-secreting pituitary tumours, and this is of potential importance in their management.