Cushing Syndrome Quiz

Understanding Cushing Syndrome

Cushing syndrome, also known as hypercortisolism, is a condition that occurs from exposure to high cortisol levels for a long time. The most common cause is the use of oral corticosteroid medication. The body can also produce too much cortisol. This quiz is designed to test your knowledge of its causes, symptoms, diagnosis, and treatment, which are critical topics for medical students, healthcare professionals, and anyone preparing for board examinations.

Etiology of Hypercortisolism

The causes of Cushing syndrome can be broadly categorized as either exogenous or endogenous. Understanding this distinction is the first step in a diagnostic workup.

• Exogenous Cushing Syndrome: This is the most common form, resulting from the long-term use of high-dose corticosteroid medications (e.g., prednisone) for conditions like asthma, rheumatoid arthritis, or lupus.
• Endogenous Cushing Syndrome: This is rarer and occurs when the body itself produces excessive cortisol. The primary causes are:
  • Pituitary adenoma (Cushing’s disease): A benign tumor on the pituitary gland produces excess adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol. This accounts for about 70% of endogenous cases.
  • Adrenal tumors: A tumor on one of the adrenal glands directly produces excess cortisol. This can be benign (adenoma) or malignant (carcinoma).
  • Ectopic ACTH syndrome: A tumor outside the pituitary gland (e.g., in the lungs, pancreas, or thyroid) produces ACTH. Small-cell lung cancer is a classic cause.

Clinical Manifestations

The signs and symptoms of Cushing syndrome are numerous and affect multiple body systems. Recognizing these clinical features is crucial for suspecting the diagnosis.

• Weight gain and fatty tissue deposits: particularly around the midsection, upper back (buffalo hump), and in the face (moon facies).
• Skin changes: Thin, fragile skin that bruises easily, purple or pink stretch marks (striae) on the abdomen, thighs, breasts, and arms, and poor wound healing.
• Metabolic changes: New-onset or worsening high blood pressure (hypertension) and high blood sugar (hyperglycemia).
• Musculoskeletal effects: Severe fatigue, muscle weakness (proximal myopathy), and bone loss (osteoporosis).
• Neuropsychiatric symptoms: Irritability, anxiety, depression, or cognitive difficulties.

Diagnostic Approach

Confirming hypercortisolism and then determining its cause involves a stepwise approach. No single test is perfect, so multiple tests are often required.

1. Step 1: Confirm Hypercortisolism. Initial screening tests include:
   • 24-hour urinary free cortisol (UFC) measurement.
   • Late-night salivary cortisol measurement.
   • Low-dose dexamethasone suppression test (LDDST).
2. Step 2: Determine the Cause. Once hypercortisolism is confirmed, the next step is to measure plasma ACTH levels.
   • If ACTH is low, the cause is likely an adrenal tumor (ACTH-independent).
   • If ACTH is normal or high, the cause is ACTH-dependent (either a pituitary tumor or an ectopic source).
3. Step 3: Differentiate Pituitary vs. Ectopic Source. If ACTH is elevated, further tests like a high-dose dexamethasone suppression test, CRH stimulation test, and imaging (MRI of the pituitary, CT of chest/abdomen) are used to locate the source.

Treatment Strategies

The goal of treatment is to lower the high cortisol levels in the body. The specific approach depends on the underlying cause. For pituitary adenomas, transsphenoidal surgery is the first-line treatment. Adrenal tumors are typically treated with surgical resection (adrenalectomy). For ectopic ACTH-producing tumors, the primary tumor must be located and removed. If surgery is not an option or is unsuccessful, medical therapy to inhibit cortisol synthesis (e.g., ketoconazole, metyrapone) or radiation therapy may be used.

Prognosis and Long-term Management

With successful treatment, the signs and symptoms of Cushing syndrome usually improve over time. However, recovery can be a slow process. Patients require long-term follow-up to monitor for recurrence and manage associated comorbidities like hypertension, diabetes, and osteoporosis. If the adrenal glands were removed or suppressed, patients might need lifelong glucocorticoid replacement therapy.

Complications of Untreated Cushing Syndrome

Leaving Cushing syndrome untreated can lead to severe health problems. These include an increased risk of heart attack and stroke, blood clots, serious infections, bone fractures due to osteoporosis, and significant impacts on mental health and quality of life. Early diagnosis and treatment are therefore essential to prevent these long-term complications.

This information is for educational and study purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.