Endocrine Abstracts

Dopamine agonists are the treatment of choice for prolactinomas and surgery is warranted only when the response to medical therapy is poor, not tolerated, or in those with compromised vision or with extensive invasion. We describe the two cases of a giant prolactinoma treated with cabergoline alone and next to surgery and gamma-knife.

Case 1: A 30-year-old man admitted with headache and visual defect, cranial magnetic resonance imaging (MRI) revealed a invasive giant-adenoma with 50% cystic mass and dimensions of 47×30×27 mm in size on the sellar area. Prolactin level was >1000 ng/ml with other tests showed no abnormality other than hypogonadism. Cabergoline was started with 1gram per week with twice dosing and was increased up to 3 g. After 3 months MRI revealed significant reduction in tumor size (30×22×18 mm) with subacute hemorrhagic changes. Prolactin level was down to 25 ng/ml at 3rd month and to 4 ng/ml at 6th month. Hypogonadism findings improved, and visual field showed marked improvement.

Case 2: Another man with 34 years was evaluated by a neurosurgeon at another institution due to headache and confusion. He has operated due to significant signs of compression with invasive giant-prolactinoma containing large cystic areas and 45×33×20 mm in size detected with cranial MRI. Preoperative prolactin level was >1000 ng/ml. Cabergoline was started immediately postoperatively and gama-knife surgery was performed subsequently. In this case MRI findings at 3rd and 6th months were not showed improvement in tumor size and prolactin level was 250 ng/ml when admitted to us.

In the first case, cabergolin treatment has been effective for giant prolactinoma although containing cystic structures, in the second case it could not improvement in tumor size. Compared to the two cases, can be suggested that early surgical intervention or radiotherapy may have caused this ineffectiveness.