Ectopic ACTH syndrome associated with large-cell neuroendocrine carcinoma of the lung.
Although ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is a well-known paraneoplastic phenomenon, an association with large-cell neuroendocrine carcinoma of the lung (LCNEC) has not been reported. We describe a 63-year-old man with metastatic LCNEC to the left temporomandibular joint (TMJ) who presented with progressive muscle weakness and bilateral lower leg edema for 2 weeks. He did not have a typical Cushingoid appearance nor used diuretics. His newly noted hypertension, hypokalemia (plasma potassium (K) concentration 1.8 mEq/L) with renal K wasting, and metabolic alkalosis suggested a state of mineralocorticoid excess. His plasma renin activity and aldosterone concentrations were low, but cortisol and ACTH levels were extremely elevated, consistent with ACTH-dependent Cushing's syndrome. Nonsuppressible plasma cortisol level and normal sella turcica on magnetic resonance imaging pointed to EAS. A strongly positive stain for ACTH from the metastatic left TMJ mass supported LCNEC-related EAS. His hypokalemia and hypertension were controlled with spironolactone and K supplementation. This is the first reported case of EAS in LCNEC and should be kept in mind as a cause of hypokalemia in lung cancer patients.
Lin
Chin-Sheng
CS
Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Yao
Nai-Shun
NS
Cheng
Ming-Fang
MF
Lin
Shih-Hua
SH
D000182:ACTH Syndrome, Ectopic / Q000097:blood / Q000209:etiology*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D018287:Carcinoma, Large Cell / Q000150:complications* / Q000378:metabolism / Q000628:therapy; D018278:Carcinoma, Neuroendocrine / Q000150:complications* / Q000378:metabolism / Q000628:therapy; D006801:Humans; D006973:Hypertension / Q000209:etiology; D007008:Hypokalemia / Q000209:etiology; D008175:Lung Neoplasms / Q000150:complications* / Q000378:metabolism / Q000628:therapy; D008297:Male; D008875:Middle Aged; D013704:Temporomandibular Joint / Q000378:metabolism / Q000473:pathology
D000324:Adrenocorticotropic Hormone