SAT-LB49 Persistent vs Recurrent Cushing’s Disease Diagnosed Four Weeks Post-Partum

Background: Cushing’s disease (CD) recurrence in pregnancy has previously been described and is thought to be associated with predictable estradiol fluctuations during gestation. CD recurrence in the immediate post-partum period has been reported once, but never in a patient with documented dormant disease during pregnancy.Clinical Case: A 30 year old woman with recently diagnosed pre-diabetes presented with weight gain, dorsal hump, depression, oligomenorrhea, and lower extremity weakness. Diagnostic tests were consistent with CD. Results included: three elevated midnight salivary cortisols: 0.33, 1.38 and 1.10 ug/dL (<0.010 - 0.090); 1-mg dexamethasone suppression test (DST) with cortisol 14 ug/dL (<1.8); elevated 24-hr urine cortisol 825 ug/24 hr (6-42); and ACTH 35 pg/mL (7.2-63.3). MRI of the pituitary gland revealed a left 4mm focal lesion. After transsphenoidal resection (TSA), day 1, 2, and 3 morning cortisol values were 18, 5, and 2 ug/dL, respectively. Pathology did not show a definitive pituitary neoplasm. She was rapidly titrated off hydrocortisone (HC) by six weeks post-resection. Her symptoms steadily improved. She resumed normal menses and conceived unexpectedly around 3 months post-TSA. She complained of severe fatigue in her late 2(nd) trimester. Given low 24-hr urine cortisol of 15 ug/24 hr at 36 weeks gestation, she was started on HC. She was induced at 40 weeks gestation for oligohydramnios and subsequently delivered a healthy baby boy. HC was discontinued immediately after delivery. Around four weeks post-partum she developed symptoms concerning for CD. Diagnostic tests showed elevated midnight salivary cortisol of 0.206 and 0.723 ug/dL and 24-hour urine cortisol of 400 ug/24 hr. MRI pituitary illustrated a 3mm adenoma in the left posterior gland which was thought to represent growth of residual tumor not clearly seen on post-op MRI. During repeat TSA, a discrete lesion was found and resected. Pathology confirmed corticotroph adenoma with MIB-1 < 3%. Post-operative day 1, 2, and 3 cortisol levels were 26, 10 and 2.8 ug/dL, respectively. She was tapered off HC within one month. Her symptoms improved only slightly and she continued to report weight gain, muscle weakness, and fatigue. Three months after repeat TSA, biochemical data showed 1 out of 2 midnight salivary cortisols elevated at 0.124 ug/dL and elevated urine cortisol of 76 ug/24 hr. MRI pituitary demonstrated a 3 x 5 mm left enhancement, concerning for residual or enlarged persistent tumor. Conclusion: We describe the first report of recurrent CD that was quiescent during pregnancy, and subsequently diagnosed in the immediate post-partum period. Treatment options for persistent or recurrent CD include aggressive surgical resection, radiation and/or medical therapy. In the context of additional family planning for this otherwise healthy, reproductive-age woman, ideal management options remain uncertain.