Abstract
Background: Prolactinomas are the most frequently occurring pituitary adenomas and consist of nearly 40% of all pituitary adenomas. Their prevalence varies from approximately 60 to 100 inhabitants per million. Objectives: This study aimed to determine demographic and clinical features of patients with prolactinoma. In addition, it targeted to determine success percentage of medical therapy and frequency of dopamine agonist (DA) resistance. Materials and Methods: Records of 646 patients who were admitted to Endocrinology and Metabolism Disease department of two hospitals in Turkey between 2007 and 2014 were evaluated retrospectively. Data of the study were obtained from file records for 53% patients and ICD-10 diagnosis code of electronic database of the hospital in 47% of patients. Results: Of patients who received medical therapy, 91.7% (n = 394) had received cabergoline (CAB) and 8.6% (n = 55) had received bromocriptine (BMC). While normalization rate of prolactin was 92.7% with medical therapy, size of the adenoma completely regressed in 59.7% patients. Size of the adenoma decreased more than 50% in 56% patients. Resistance was detected against DA drugs in 6.9% patients. DA resistance found in 3.9% of patients with microprolactinoma and 27% of patients with macroprolactinoma. Conclusion: Success percentage of CAB therapy was found greater than BMC therapy in patients with microprolactinoma, which was in line with the literature. And, frequency of DA resistance was found to be lower in patients with microprol- actinoma and greater in patients with macroprolactinoma than that reported in the literature.