RAPID RESOLUTION OF VISUAL ABNORMALITIES WITH MEDICAL THERAPY ALONE IN PATIENTS WITH LARGE PROLACTINOMAS

Large prolactin-secreting pituitary adenomas with suprasellar extensio n are often complicated by visual field defects, for which surgical de compression is the accepted treatment. However, surgical management of large prolactinomas is often not curative. This report describes a gr oup of six unselected male patients who presented with visual field de fects and reduced visual acuity due to large pituitary tumours with su prasellar extension. All six patients also had loss of libido and/or i mpotence. A rapid serum prolactin estimation enabled thr diagnosis of prolactinoma to be made, and CT revealed a large pituitary adenoma wit h suprasellar extension. The patients were treated with bromocriptine, in doses increasing from 2.5 to 20 mg daily, as the sole therapy. Sym ptoms were relieved and serum prolactin levels were restored to normal or near normal; visual field defects resolved and visual acuity recov ered in all patients. A repeat CT showed evidence of tumour shrinkage especially of the suprasellar extension, in all the patients. A diagno sis of prolactinoma should always be considered in a patient with a la rge pituitary tumour. The clinical history and a rapid prolactin assay will confirm the diagnosis. Treatment with bromocriptine leads to rap id improvement in perimetry and visual acuity as well as tumour shrink age, obviating the need for pituitary surgery.