THU021 Mysterious Resolution Of Cushing’s Disease

Abstract

Abstract Disclosure: D.R. Whiteman: None. T. Hoang: None. V. Del Signore: None. P.V. Shah: None. Cushing’s disease is a unique problem to the endocrinologist. Clinical acumen is needed to guide correct therapy. We describe a case of Cushing’s disease in a young reproductive female with abnormal menses and obesity. Post-operative surgical pathology did not confirm her disease, but her menses normalized and biochemical evidence of disease did not persist. Case Presentation: A 24 year old female presented with irregular menses since menarche. She had 2-3 menstrual cycles per year prior to oral contraceptive pills (OCPs). She stopped OCPs and failed to conceive for > 1 year. Other symptoms included chronic fatigue, increased weight gain, abdominal striae, and hirsutism on her chin, arms, abdomen, and nipples. Prior evaluation showed positive progesterone withdrawal. Endocrine work-up included low dose 1mg dexamethasone suppression (LDST), total testosterone, FSH, LH, estradiol, sex hormone binding globulin, 17-hydroxyprogesterone, DHEA-sulfate, IGF-1, TSH, free T4, prolactin, and hemoglobin A1c. Work-up only positive for LDST: cortisol of 3.8 ug/dL. Additional screening tests included: 24 hour urine cortisol collection of 32 ug/24hr but volume not reported and late-night salivary cortisol (LNSC) of >0.1 ug/dL. Three more LNSC tests resulted as 0.212, 0.739, and 0.154 ug/dl. Confirmatory testing with 8mg Dexamethasone suppression test was positive: cortisol of 0.4 ug/dL. ACTH was 21.6 pg/mL, consistent with ACTH dependent disease. A pituitary MRI with and without contrast was negative for pituitary adenoma. Next, she completed inferior petrosal sinus sampling (IPSS) that lateralized to the left sella. Her central to peripheral ACTH ratio was > 2 and lateralized to the left with a ratio > 1.4. She had transsphenoidal pituitary resection and postoperative cortisol initially dropped to 5.5 ug/dL, but increased to 13.3 ug/dL prior to discharge. No glucocorticoid replacement required. Surgical pathology demonstrated non-neoplastic pituitary tissue with no pathologic change. Post-operative IPSS revealed all cortisol levels < 2.0 ug/dL. Two post-operative AM cortisol measurements were 5.4 ug/dL and 10.8 ug/dL suggestive of no remission. Interestingly, 2 months post-operatively repeat screening tests were negative: LDST cortisol of 0.6 ug/dL, salivary cortisol <0.010 ug/dL, and 24 hour urine cortisol 18 ug/24 hour. Furthermore, menses returned post-operatively. Discussion: Missing a diagnosis of Cushing’s disease results in increased morbidity. The diagnostic process can be both complex and invasive. Localization of the adenoma and resection are needed for cure. Standard practice dictates confirmation with pathology and biochemical remission. Interestingly, initial cortisol levels did not suggest remission, but later biochemical testing ruled out ongoing Cushing’s disease. Due to inadequate tissue data, true etiology of disease and remission remains a mystery. Presentation: Thursday, June 15, 2023