ODP339 Nonfunctioning Giant Adenomas

INTRODUCTION: Giant pituitary tumors (GA), those with 4 cm or more on the largest axis, exhibit extension beyond the sella turcica and invade structures adjacent to it. OBJECTIVES: To evaluate demographic, clinical, and imaging variables in a cohort of nonfunctioning GA(NGA) patients. METHODS: We conducted a retrospective and observational study of patients with NGA followed in our tertiary center between 2005 and 2021. We evaluated variables related to diagnosis, treatment, and follow-up. RESULTS: We found 48 patients diagnosed with NGA. Most patients were men (n=35, 73%), and meanage at diagnosis 55.5 ± 11.8 years (35-83). Symptoms such as headache and visual alteration were present within 13 years of diagnosis. The BMI was higher than 30 in 10 cases, two with morbid obesity. Among the comorbidities, 10 patients had diabetes mellitus and one glucose intolerance; hypertension was present in 20 cases and depression in 7. Polymedication was verified in 20 patients. Pituitary MRI revealed the largest tumor axis between 4-4.9 cm in 33 patients, 5-5.9 cm in 9, and equal or greater than 6 cm in 6. In 14 cases, there was intraventricular extension, invasion of the sphenoid sinus in 11, cavernous sinus in 21, frontal lobe in 1, temporal region in 6, clivus in 3, retroclivus in 3, and rhinopharynx in one. Hyperprolactinemia was detected in 17 cases (maximum value: 70.8 ng/mL). Only three patients presented all hormonal axes intact. Respectively, 9, 15, 11, and 8 patients presented 1, 2, 3, or 4 deficient axes. Hypocortisolism was present in 18 cases, GH deficiency in 16, hypothyroidism in 32, hypogonadism in 35, and hypoprolactinemia in 3. Four patients had diabetes insipidus. Ten cases of the 44 who underwent surgery underwent two interventions and 4 cases, 3. Nine patients underwent radiotherapy. After the first surgery, 26 patients had follow-up greater than 12 months (13 to 214 months). The last image showed a giant lesion in 7 cases, macroadenoma with a larger axis less than 4 cm in 15 cases, a lesion restricted to the sella in 3 cases, and 1 case without lesion. CONCLUSION: In our cohort, the results show the handling difficulty of NGA, determined by the complex removal of the lesion, high degree of invasion to adjacent structures, and tumor regrowth. Sequential therapeutic decisions in this group of patients require a qualified multidisciplinary team to maximize the patients’ life expectancy and quality of life while working on sharing experiences and investing in the tumor molecular characterization and new molecules that add to the poor therapeutic arsenal available. Presentation: No date and time listed