Large macroprolactinoma treated with bromocriptine alone

We report a case of a large macroprolactinoma in a 44-year-old male photographer who presented with affected colour perception and a central scotoma of the right eye. An initial computerised tomographic (CT) scan showed an enormous mass lesion extending from the nasopharyngeal area to the third ventricle, with destruction of the skull base. The initial serum prolactin level was 29 180 micrograms/L (normal < 15.8 micrograms/L) while other pituitary hormones were within normal ranges. The patient was treated with oral bromocriptine with prompt resolution of visual defects while significant reductions in tumour size (> 50%) and prolactin level (> 99%) were achieved over a one-year period. This represents one of the highest serum prolactin levels reported in the literature in a patient with a prolactin-secreting pituitary tumour and illustrates the remarkable efficacy of dopamine agonist therapy in patients with large macroprolactinomas.