|
KMID : 0356620070220050359
|
|
Journal of Korean Society of Endocrinology
2007 Volume.22 No. 5 p.359 ~ p.364
|
|
|
A Case of Ectopic ACTH Syndrome Associated with Small Cell Lung Cancer Presented with Hypokalemia
|
|
Yang Hong-Jun
Sung Hea-Jung
Kim Ji-Eun
Lee Hyo-Jin
Park Jin-Min
Park Chan-Kwon
Roh Eun-Suk
Cho Jae-Hyoung
Ko Seung-Hyun
Song Ki-Ho
Ahn Yu-Bae
|
|
|
Abstract
|
|
|
|
We report a case of a 73-year-old female patient who was diagnosed with ectopic ACTH syndrome caused by small cell lung cancer. We initially presumed that the patient was in a state of mineralocorticoid excess, because she had hypertension and hypokalemic alkalosis. This was however excluded because her plasma renin activity was not suppressed and her plasma aldosterone/plasma renin activity ratio was below 25. Moreover, her 24 hour urine free cortisol level was elevated and her serum cortisol levels after a low dose dexamethasone suppression test, were not suppressed. Furthermore, her basal plasma ACTH and serum cortisol levels increased and her serum cortisol level after a high dose dexamethasone suppression test was not suppressed. We performed studies to identify the source of ectopic ACTH syndrome and found a 3 cm-sized mass in the patient’s right lower lobe of her lung, which was eventually diagnosed as small cell lung cancer following a bronchoscopic biopsy. In conclusion, Cushing’s syndrome, and in particular ectopic ACTH syndrome, must be considered in the differential diagnosis of mineralocorticoid-induced hypertension. The excessive cortisol saturates the 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) activity, which in turn, inactivates the conversion of cortisol to cortisone in the renal tubules. Moreover, excessive cortisol causes binding to the mineralocorticoid receptors, causing mineralocorticoid hypertension, characterized by severe hypercortisolism.
|
|
|
KEYWORD
|
|
|
Ectopic ACTH syndrome, hypokalemia, small cell Lung cancer
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
  
|
|