MON-324 Management and Therapeutic Response Comparison in Prolactinomas According to Tumor Size

Prolactinomas are the most common type of functioning pituitary adenomas and up to 50% of all adenomas in clinical practice. Prolactinomas are more prevalent in women; nonetheless, they may occur at any age and in both genders, and represent the most common cause non-physiological hyperprolactinemia. Prolactin-secreting adenomas are classified by their tumor size as follows: microprolactinomas (<1 cm), macroprolactinomas (>1cm) and giant prolactinomas (>4 cm). The clinical presentation of these tumors might differ from age, sex and size. Dopamine agonists, such as cabergoline or bromocriptine, have become the first line of treatment, since these agents decrease tumor size and prolactin (PRL) secretion. In Mexico, recent studies have focused on giant prolactinomas but there is missing data of the clinical and biochemical manifestations of the tumor size-effect within the three types of prolactinomas in our population. Objective: To determine the effect of the tumor size in the clinical and biochemical presentation, and the follow up in prolactinomas. Methods: This an observational, retrospective, retrolective study. Results: Patients were classified according to their tumor size and 489 patients with confirmed diagnosis of prolactinoma were included. The mean age was 36+-12 years old and 86% were women. The size was different among sex with 14 (2.9%) and 259 (52.9%) patients with microprolactinoma and 34 (6.9) and 152 (31.1%) with macroprolactinoma in men and women, respectively (p <0.001). The median PRL levels were higher among patients with bigger tumors, 115 (97-150) ng/mL for microprolactinomas, 219 (115-777) ng/mL for macroprolactinomas and 2000 (154-4000) ng/m for giant prolactinomas (p <0.001). Clinically, hypogonadism was more prevalent in women with bigger tumor size (p <0.001), as well as visual defects (p <0.001) and headache (p 0.008). Conclusion: The tumor size of prolactinomas affects the clinical and biochemical presentation as well as the years of follow up required. References 1. Lopes M.B.S. (2019). Pathology of prolactinomas: any predictive value? Pituitary doi: 10.1007/s11102-019-00997-1