A man suffering from extremely high ACTH level but normal pituitary gland functioning is actually suffering from Ectopic synthesis of ACTH by small cell lung carcinoma.
ACTH hormone is used to stimulate the adrenal glands to release cortisol, which is vital for functioning of major body tissues and organs. Small cell lung cancer occurs mainly due to inappropriate secretion of ACTH hormone, which causes formation of neuroendocrine tumor. These can be detected only by MRI (Magnetic Resonance Imaging) OR CT (Computed tomography) scan. This condition can be treated only by consumption of cortisol lowering drugs. The majority of pituitary gland metastasis cases with secondary adrenal insufficiency have lung cancer as their primary tumor, which are misdiagnosed as pituitary adenomas.
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