Summary
Introduction. Prolactinomas are benign pituitary tumors that secrete prolactin and are the most common type of pituitary secreting tumors, making up about half of all cases. These tumors cause hyperprolactinemia, they can be detected by finding elevated prolactin levels in the blood and a mass in the pituitary gland on imaging studies. If the prolactinoma is symptomatic, the first-line treatment is medical therapy with dopamine agonists, with cabergoline being the most effective. Cabergoline has been shown to normalize prolactin levels in 77–95% of prolactinoma cases.
Case report. A 47-year-old man contacted an endocrinologist after being diagnosed with thyroid nodules. He had been experiencing general weakness and intermittent headaches. Blood tests revealed decreased levels of thyroid stimulating hormone and free thyroxine, indicating central hypothyroidism and the presence of a pituitary dysfunction. An MRI revealed a pituitary macroadenoma 20×16×18 mm, pressing on the optic chiasm. The patient was prescribed cabergoline 2 mg/week, hydrocortisone, and levothyroxine replacement therapy. After a month and a half of the treatment, the patient showed improvement in well-being and a decrease in prolactin levels to 39.7 mU/L. Seven months after the treatment, MRI was repeated and revealed a significant reduction in the pituitary adenoma. It was decided to continue medical therapy for the treatment of macroprolactinoma.
Discussion and conclusions. Cabergoline is a potent medication that activates dopamine D2 receptors and is used to treat hyperprolactinemia. It is the firstline treatment for macroprolactinomas due to its high efficacy and minimal adverse effects. This case demonstrates the efficacy of cabergoline, as the patient’s prolactin levels dropped significantly in less than two months of treatment and the adenoma size was markedly reduced within seven months.
