Category: Adrenal Disorders
Objective : We report a unique case of paraneoplastic Cushing’s syndrome in the setting of poorly differentiated neuroendocrine carcinoma.
Methods : n/a
A 24yr old female presented to the hospital April 2018 with palpitations, weight loss, and abdominal pain. She was found to have Grave’s disease along with a right adnexal mass, multiple liver/lung lesions, retroperitoneal lymphadenopathy, a right parietal brain lesion, and a right 2cm thyroid nodule. Biopsy of the retroperitoneal lymph node revealed metastatic poorly differentiated carcinoma with neuroendocrine differentiation. FNA of the thyroid nodule confirmed metastasis.
In May 2018, she had the 1st cycle of carboplatin/etoposide and in June 2018 had her 2nd cycle. She was started on high dose Decadron (4mg BID) during her 1st cycle of chemotherapy due to vasogenic edema from her brain metastasis. 2 weeks after her 2nd cycle of chemotherapy, she presented to the hospital with recurrent seizures along with multiple metabolic abnormalities including new onset severe hypokalemia 1.7 mmol/L (3.5-5.0 mmol/L) and severe metabolic alkalosis with a bicarbonate level of 42 mmol/L (22-28 mmol/L) and pH of 7.72 (7.35-7.45). She was persistently hypertensive as well as hyperglycemic requiring insulin therapy. During her hospital stay she required aggressive potassium repletion with potassium chloride 40 mEq TID.. Given the neuroendocrine nature of her poorly differentiated carcinoma, ectopic Cushing’s syndrome was thought to be a cause of her metabolic abnormalities. She was placed on spironolactone 50mg TID with improvement in her potassium. Labs were consistent with Cushing’s syndrome with a 24hr urine free cortisol of 3,132.1 ug/24hr (4-50 ug/24hr) ,midnight cortisol of 51.3 ug/dL (5-23 ug/dL) and 9AM cortisol of 51.1 ug/dL (5-23 ug/dL). An ACTH was 132 pg/mL (6-50 pg/mL). These cortisol values were elevated despite being on high doses of Decadron. After confirmatory testing, she was started on metyrapone 250mg q6hr to control hypercortisolism. She remained on metyrapone for a few days with normalization of potassium and bicarbonate levels. She was discharged from the hospital only on spironolactone (due to inability to get insurance approval for metyrapone) and resumed chemotherapy. After 5 cycles of chemotherapy and decreased size in her metastatic lesions, her potassium and bicarbonate levels remain normal and she is normotensive and euglycemic.
Discussion : n/a
Conclusion : This is a rare case of ectopic Cushing’s syndrome with clinical improvement after treatment of the underlying malignancy. This case shows the importance of evaluating for ectopic Cushing’s syndrome in the setting of unexplained hypokalemia.
Cooper University Hospital
Cherry Hill, New Jersey