SAT-048 Synchronic Pituitary Tumors: a Case Series from a referral center

Abstract Disclosure: E. Lamback: None. C. Aloan: None. N. Ventura: None. F. Andreiuolo: None. M. Gadelha: None. Synchronous pituitary tumors (SPT) are rare, accounting for only 1-2% of pituitary lesions. The aim of this study was to describe our experience with SPT cases diagnosed between April 2020 and January 2025 at a referral center. During this period, 844 sellar surgeries were performed, of which 674 were for pituitary tumors. Among these, eight cases (1.2%) of SPT were identified. The cohort consisted of six males and two females, with a median age of 67 (range: 42-74). The presenting symptoms were acromegaly (in three cases), Cushing disease (in one case) and visual disturbances (in three cases). One case was diagnosed incidentally (with the tumor abutting the optic chiasm). Therefore, four patients (50%) had functioning tumors and four (50%) had non-functioning pituitary tumors. Reviewed preoperative magnetic resonance imaging showed two distinct lesions in only two cases. All patients underwent transsphenoidal surgery. Immunohistochemical profiling showed the following tumor combinations: gonadotroph and lactotroph (n=2); gonadotroph and corticotroph (n=2); gonadotroph and densely granulated somatotroph (n=1); gonadotroph and sparsely granulated somatotroph (n=1); somatotroph with co-expression of PIT1 and SF-1, and plurihormonal (SF-1+GATA3+PIT1) (n=1); and corticotroph and lactotroph tumors (n=1). Surgical outcomes were favorable in 50% of cases. In conclusion, SPT are uncommon and often present as non-functioning tumors or with acromegaly. Preoperative identification remains challenging in most cases. Histopathological examination commonly reveals gonadotroph tumors in association with hormone-secreting tumors. Presentation: Saturday, July 12, 2025