Twenty six patients with macroprolactinomas treated with D2 receptor agonists were examined, 4 patients were later excluded from the group since their treatment was initiated before MRI examination of the brain. Intratumoral hemorrhage during treatment with D2 receptor agonists was observed in 3 (14 %) cases before treatment onset and in 12 (55 %) cases during the application of D2 receptor agonists. In 2 patients, bleeding into tumor was associated with clinical symptoms for which a neurosurgical revision was necessary, with a positive clinical outcome. In conclusion, MRI can be considered the optimal imaging method for diagnosing macroprolactinomas, monitoring the results of their treatment with D2 receptor agonists and the possible complications of this therapy.

        Key words: macroprolactinoma, D2 receptor agonists, magnetic resonance imaging, bleeding into adenoma