Periodic hypokalemia associated with cyclic Cushing's syndrome

Area of Science:

• Endocrinology
• Internal Medicine
• Rare Diseases

Background:

• Cyclic Cushing's syndrome is a rare endocrine disorder characterized by fluctuating cortisol levels.
• Ectopic adrenocorticotropic hormone (ACTH) secretion can cause Cushing's syndrome, often presenting with hypertension, hypokalemia, and edema.
• Diagnosing cyclic forms can be challenging due to intermittent symptom presentation.

Purpose of the Study:

• To report an extremely rare case of cyclic Cushing's syndrome.
• To highlight the diagnostic challenges associated with ectopic ACTH secretion causing periodic symptoms.
• To demonstrate successful management of cyclic Cushing's syndrome.

Main Methods:

• Clinical presentation of a 69-year-old woman with periodic hypertension, edema, and hypokalemia.
• Laboratory investigations revealed fluctuating plasma ACTH and cortisol levels.
• Endocrinological assessments and imaging studies were performed, including CT scans.
• Treatment with metyrapone and dexamethasone was initiated.

Main Results:

• The patient exhibited periodic hypertension, edema, and hypokalemia, correlating with elevated ACTH and cortisol.
• Despite supplementation, hypokalemia recurred, accompanied by Cushingoid features.
• Imaging failed to identify an ectopic source of ACTH.
• Metyrapone plus dexamethasone effectively controlled hypercortisolemia and symptoms.

Conclusions:

• This case represents a rare presentation of cyclic Cushing's syndrome due to presumed ectopic ACTH secretion.
• The intermittent nature of symptoms posed diagnostic difficulties.
• Pharmacological management with metyrapone and dexamethasone proved effective in controlling the condition.