internal medicine resident New York Presbyterian Brooklyn Methodist Hospital Brooklyn, New York, United States
Introduction : Cushing's Syndrome is most commonly caused by cushing's disease, however 5-15% of cases are due to ectopic adrenocorticotropic hormone (ACTH) Syndrome (EAS). EAS associated with non-pituitary tumors are rare and most typically seen in thoracic tumors. We present an extremely rare cause of EAS secondary to metastatic urothelial bladder cancer.
Case(s) Description : A 68-year-old male with a past medical history of cerebral palsy, Parkinson’s disease, hyperlipidemia, hypertension, and metastatic urothelial bladder cancer to the lung and liver was admitted to the hospital for a cystectomy. Endocrinology was consulted for hypercalcemia with a serum calcium of 11.7 mg/dL, albumin 2.1 g/dL and corrected calcium of 13.2 mg/dL. Further workup was obtained notable for PTHrp 18.3pmol/L, PTH< 6.3pg/mL, and vitamin D 25/1,25 were within normal limits. The patient was diagnosed with hypercalcemia of malignancy and was treated with calcitonin and pamidronate. CT and MRI abdomen showed an incidental right adrenal nodule of 1.2 cm, which promoted evaluation of cortisol secretion. In addition, the patient was hypokalemic 2.9 mmol/L. No striae, facial plethora or bruising was noted. Labs were notable for an ACTH level that was inappropriately normal at 42.5 pg/mL, am cortisol 30 ug/dL, and 24-hour urinary free cortisol 149.6 ug/d. The patient failed to suppress with a low dose dexamethasone suppression test with an am cortisol of 20.78 ug/dL. We followed with a high dose dexamethasone test, which resulted in a drop in am cortisol from 25 ug/dL to 24.6 ug/dL. A pituitary MRI was nondiagnostic due to motion artifacts. However, considering the high dose dexamethasone test had < 50% decrease in am cortisol it was determined that this was in fact EAS and most likely secondary to metastatic urothelial bladder cancer.
Discussion : The association of cushing's syndrome with EAS was first discovered in 1962 and since then there remains limited research regarding these tumors due to the rarity of this syndrome. These patients have been noted to have increased risk of infection and venous thromboembolisms possibly contributing to their increase in morbidity.Elevated ACTH was found to indicate extensive disease and poor response to treatment. EAS is a rare cause of Cushing’s syndrome and is most commonly seen with bronchial carcinoid and small cell lung carcinoma. This patient presented with EAS secondary to bladder cancer, which is an extremely rare cause of EAS. Overall it is important to document these cases in order to help clinicians in the future more effectively diagnose and treat EAS.
