MON-056 Pregnancy’s potential beneficial effect in the remissionof microprolactinoma in women

Abstract Disclosure: F. Mousavi: None. F. Antoni: None. R. Haykal: None. Introduction: Prolactinomas are the most common secreting type of pituitary tumor and can lead to significant endocrine dysfunction. Studies have shown that prolactinomas may undergo spontaneous remission after pregnancy, particularly in patients treated with dopamine agonists before conception occurs. This report highlights a case in which a patient treated with Cabergoline who had a pregnancy that resulted in the normalization of serum prolactin levels post-delivery, despite no change in adenoma size. Case Description: A 31-year-old woman with a history of pituitary microadenoma, hyperprolactinemia, and recurrent miscarriages was referred to the endocrine clinic for a medically assisted conception evaluation.The patient was diagnosed with an incidental pituitary microadenoma at age 20 when she had an MRI done in the setting of an evaluation for lightheadedness. She reported irregular, heavy menses by then, but denied galactorrhea, headaches, or visual changes. Laboratory records confirmed chronic hyperprolactinemia since her adenoma diagnosis, but she had never received treatment prior to establishing care at an endocrine clinic.Her initial workup revealed consistently elevated prolactin levels of 69.8 ng/mL. Drug-induced or other causes of hyperprolactinemia were excluded. MRI of the pituitary revealed a 5.6 mm, hypoenhancing sellar mass without suprasellar or parasellar extension, confirming the diagnosis of microprolactinoma. Cabergoline was prescribed, resulting in normalization of her prolactin levels. Four months later, spontaneous pregnancy was achieved. Cabergoline was discontinued, and she was monitored closely during an uncomplicated pregnancy, which resulted in the birth of a healthy baby.However, she was unable to breastfeed and returned for a follow-up three months post-delivery. Physical examination revealed no abnormalities, including normal vision. Repeated pituitary function testing showed normalized prolactin levels. An MRI of the pituitary demonstrated no change in adenoma size compared to pre-pregnancy imaging.Discussion and Conclusion: Studies have shown that pregnancy may have a potentially beneficial effect on prolactinomas. The delivery and abrupt cessation of high gestational estrogen exposure can lead to focal necrosis or apoptosis of adenomatous lactotroph cells. While some studies suggest that smaller adenomas and the normalization of pituitary MRI findings after pregnancy are associated with remission, our patient's adenoma size did not change. Nevertheless, pregnancy led to normalization of prolactin levels.In conclusion, post-pregnancy, it is important to measure serum prolactin after breastfeeding has ceased to assess for remission. Regular monitoring ensures sustained normalization of prolactin levels. If prolactin levels remain elevated, further dopamine agonist therapy may be necessary. Presentation: Monday, July 14, 2025