ODP545 Ectopic Cushing's Syndrome in Small Cell Lung Cancer: A Frequently Missed Diagnosis

Abstract

Abstract A 61-year old woman, heavy smoker (40 pack-years) with a medical history of type 2 diabetes was brought to the hospital with the chief complaint of altered mental status. She had been recently diagnosed with stage IV small cell lung cancer two weeks prior but had not started chemotherapy. Physical examination was consistent with scattered petechiae and violaceous striae in bilateral upper extremities, chest, and trunk. On arrival, the patient had a blood glucose of 506 mg/dl, K 2.5 mmol/L, bicarb 23, pH 7.5, and beta-hydroxybutyrate 5.3. Further workup revealed an AM cortisol >110 and extremely elevated urine and salivary cortisol at 21000 ug/dl and 97200 ug/dl, respectively. Other remarkable labs were ACTH 480 and low TSH (0.288), free T4 (0.53), and free T3 (1.5). MRI abdomen showed bilateral adrenal masses characteristic of metastatic disease. MRI brain did not show signs of pituitary pathology. The patient was started on Ketoconazole 200 mg twice daily, Octreotide 100 mg IV every 6 hours, and Spironolactone 25 mg twice daily. Spironolactone was increased to 50 mg and later to 100 mg due to significant hypokalemia. At the same time, she was also started on urgent inpatient chemotherapy with Cisplatin/Etoposide and completed one cycle. Cortisol levels started to improve and eventually normalized. Her mental status improved as well. Although the patient symptomatically improved, her extensive-stage small cell lung cancer makes her prognosis poor in the long term. Presentation: No date and time listed