From the Guidelines
Pseudo Cushing's syndrome is a condition that mimics true Cushing's syndrome but is not caused by excess cortisol production from the adrenal glands, and it can be ruled out by considering the patient's clinical history and repeating testing to avoid inappropriate treatment 1. The diagnosis of pseudo Cushing's syndrome can be challenging due to its similarity in symptoms to true Cushing's syndrome, including central obesity, rounded face, buffalo hump, thin skin, easy bruising, and purple striae.
- The underlying conditions that can cause pseudo Cushing's syndrome include depression, obesity, and poorly controlled diabetes, which can lead to mild hypercortisolism 1.
- Standard diagnostic testing is unreliable in this population, and the use of desmopressin or dex-CRH testing may be valuable in an expert center with measurement of dexamethasone levels 1.
- Treatment of the underlying condition, such as depression or obesity, can restore normal hypothalamic-pituitary-adrenal axis function and cortisol levels, and patients can be monitored for 3-6 months to see whether symptoms resolve 1. Key points to consider in the management of pseudo Cushing's syndrome include:
- Addressing the primary cause of the condition, such as alcohol cessation, glycemic control, weight loss, or antidepressant therapy 1.
- Avoiding surgical intervention or specific anti-cortisol medications, as these are not necessary for pseudo Cushing's syndrome 1.
- Monitoring patients for 3-6 months to assess for resolution of symptoms, and further evaluating for true Cushing's syndrome if symptoms persist despite treatment of the underlying condition 1.
From the Research
Definition and Characteristics of Pseudo Cushing's Syndrome
- Pseudo Cushing's syndrome, also known as non-neoplastic hypercortisolism (NNH), refers to a group of disorders that cause mild-to-moderate ACTH-dependent hypercortisolism without an ACTH-secreting tumor 2.
- This condition is often associated with excess central adiposity and can be caused by various factors, including neuropsychiatric disorders, alcohol abuse, insulin-resistant obesity, polycystic ovary syndrome, and end-stage kidney disease 2, 3.
- Pseudo Cushing's syndrome can be difficult to distinguish from Cushing's disease, as both conditions share similar clinical and biochemical features 2, 3.
Diagnostic Challenges
- The diagnosis of pseudo Cushing's syndrome can be challenging due to the overlap of clinical features and laboratory findings with Cushing's disease 2, 4, 3.
- Useful diagnostic tests include midnight serum or salivary cortisol, dexamethasone-CRH test, and insulin tolerance test 2, 3.
- Pituitary MRI and bilateral inferior petrosal sinus sampling may not be reliable in distinguishing between pseudo Cushing's syndrome and Cushing's disease 2.
Clinical Presentation and Management
- Patients with pseudo Cushing's syndrome may present with a range of symptoms, including weight loss, hypotonia, and muscle hypotrophy 4.
- Management of pseudo Cushing's syndrome involves treating the underlying cause and reassessing hypercortisolemia after improvement in the underlying etiology 5.
- Adrenal enzyme inhibitors, such as ketoconazole, may be used to lower cortisol levels in patients with pseudo Cushing's syndrome 5.