ODP312 Giant Silent Corticotroph Adenoma: Presentation of 3 Cases

INTRODUCTION: Silent corticotroph adenoma (SCA) is a T-pit lineage cells-derived tumor without clinical presentation of Cushing's disease and normal cortisol dynamics (totally silent) or elevated ACTH/abnormal cortisol dynamics (clinically silent). SCAs account for 10-20% of silent pituitary adenomas. Giant SCAs (GSCAs), adenomas with a diameter of 4cm or more, are rare cases of pituitary adenomas. OBJECTIVE: Present the experience of a tertiary center with GSCAs. METHODS: We conducted a retrospective search of cases with a diagnosis of GSCA in the medical records of a cohort of patients with pituitary adenomas. RESULTS: We present three patients (two women, with 57 and 65 years) and a man (44 years) diagnosed with GSCA. They presented with macroadenoma associated with mass-related symptoms without clinical stigmas of hormonal dysfunction. Tumors had 4.3-5.1cm in the longest axis. In two cases, the superior tumor growth extended to the third ventricle and in only one there was a cavernous sinus invasion. The cortisol level was in the normal range in all cases; however, dynamic tests were not assessed. One patient had mild hyperprolactinemia, one had central hypothyroidism, and all cases had hypogonadism, and GH deficiency The most prevalent comorbidity was diabetes mellitus. The patients underwent transsphenoidal surgery and, in one case, two re interventions . One patient underwent radiotherapy. One patient was lost to follow-up after surgery and the other cases were followed for 39 and 53 months. At the last visit, one patient showed a 3,5cm lesion persistence and the other had a recurrent giant lesion. CONCLUSIONS: Giant SCAs have severe implications depending on their size and invasiveness, difficult total removal, greater risk of complications, significant incidence of pituitary apoplexy, short time to progression and/or higher recurrence rates after surgery, different therapies requirement including adjuvant radiotherapy, and the possibility to evolve into Cushing disease after years of inactivity. Handling this situation requires a multidisciplinary team of expert professionals, personalized decisions for each patient to minimize damage, and advances in new therapeutic agents. Presentation: No date and time listed