8024 A Case of Smoldering Clinically Silent Cushing’s Disease

Abstract Disclosure: C. Bheeman: None. I. Shafiq: None. Aggressive pituitary adenomas account for about 10% of all pituitary adenomas. These aggressive tumors are noted to have unusually rapid tumor growth rate despite optimal standard therapies including surgery, medical therapy and radiotherapy. We present a case of a 39-year-old female with no prior past medical history who initially presented with complaint of amenorrhea. She had reported she had not menstruated for the past 6 months. She also endorsed galactorrhea with nipple stimulation. A pituitary dedicated MRI revealed a pituitary adenoma measuring 2.5 x 1.7 x 1.7 cm. Hormonal work-up showed salivary cortisol on two consecutive nights that was 66 ng/dL and 52 ng/dL (reference range: 0 - 99 ng/dL) and a prolactin that was slightly elevated at 44.9 ng/mL (reference range: 4.8-23.3 ng/mL). This elevation in prolactin was thought to be due stalk effect and since her hypothalamus-pituitary-gonadal axis was suppressed, patient had a transsphenoidal resection of what was thought to be a nonfunctioning adenoma. However, the pathology of her tumor was significant for extensive ACTH staining and a Ki-67 of 11 - 15%. Her clinical course proved to be challenging as her tumor reoccurred multiple times and she eventually developed biochemical and clinical evidence of Cushing’s disease and had visual defects due to compression of the tumor on the optic nerves. This tumor was refractory to multiple surgeries, radiation treatment and chemotherapy. Through the presentation of this case, we aim to highlight the factors associated with aggressive pituitary adenomas, the current treatment guidelines and emerging medical therapies. Presentation: 6/1/2024