THU017 Severe Hypercortisolemia- A Biological Time Bomb

Disclosure: U. Munasinghe: None. S. Pittampalli: None. D. Das: None. V. Pattan: None. Cushing's disease, the most common cause of endogenous Cushing syndrome, is usually insidious and has less severe hypercortisolemia than ectopic Cushing's. 73 yr.old female with hypertension, hyperlipidemia, T2DM, and OSA on anticoagulation for recent pulmonary embolism, presented with recurrent hypokalemia and proximal muscle weakness of 3 months duration. She denied visual symptoms and headaches. BP was 158/90 mmHg, HR 92 bpm, and BMI 34.9. She had a round face with ruddy complexion, extensive bruising on her upper extremities and proximal muscle weakness. Laboratory tests showed serum bicarbonate 26 mmol/l (22-29), sodium 140 mmol/L (136-145), potassium 2.0 mom/L (3.4- 5.1), chloride 106 mmol/L (98-107), glucose 164 mg/dl. Hemoglobin A1c 9.6 %, random cortisol 46.2mcg/dL, ACTH 72.4 pg/ml (7.2-63.3), late-night salivary cortisol sample was inadequate to assess, 24-hour urine cortisol 1802 ug/24 hr (6-42). Prolactin level was 14.6 ng/ml(4.7-23.3), IGF-1 62 ng/dl (48-191), GH 0.12 ng/ml (0-3.61), FSH< 0.3 mU/ml (25.8-134.8), TSH 0.193 u/ml (0.27-4.2), Ft4 1.1 ng/dl (0.93-1.7), alpha subunit <0.15 ng/ml (<3.56). She had non-suppressed cortisol of 44.3 mcg/dL and ACTH of 113 pg/mL after overnight 8mg dexamethasone suppression test. CT angiogram chest did not reveal any pathology. MRI pituitary revealed pituitary adenoma measuring 9 x 8 mm. IPSS with desmopressin stimulation showed IPSS to peripheral prolactin ratio was greater than 1.8 verifying successful catheterization. Her central to peripheral ACTH gradient was >2 before stimulation confirming pituitary source. Her ACTH concentration gradient >1.4 between 2 sinuses lateralizing the lesion to the right. The patient was started on Osilodrostat 2mg bid for control of hypercortisolemia and subsequently treated with transsphenoidal resection of the pituitary adenoma. Surgical pathology was consistent with densely granulated corticotrophin adenoma. Initial presentation of recurrent hypokalemia, proximal muscle weakness, pulmonary embolism and severe hypercortisolemia was suspicious for ectopic Cushing’s but after initial chest imaging was negative for ectopic pathology, MRI and subsequent IPSS helped with timely diagnoses and management. Severe hypercortisolemia is an endocrine emergency carrying high mortality. Expedited diagnoses, control of hypercortisolemia, anticoagulation and antibiotic prophylaxis can be life saving before definitive treatment can be done. Presentation: Thursday, June 15, 2023