Endocrinology and metabolic for AMC MCQ

A 42 year old woman has gained weight centrally with a rounded face and a fat pad at the back of her neck, purple abdominal striae, easy bruising and weakness climbing stairs. She has new hypertension and a raised glucose. She takes no regular medication. An overnight dexamethasone suppression test fails to suppress her cortisol. What is the most likely diagnosis?

1. Depression Depression can also copy the Cushing picture, with changes in cortisol. That does not match the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off.
2. Cushing syndrome correct Correct. Weight gain around the middle, stretch marks, weak hip muscles, high blood pressure and high blood sugar, with cortisol that will not switch off, is Cushing syndrome.
3. Type 2 diabetes with obesity High blood sugar without the specific signs of Cushing syndrome. Here, the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off points elsewhere.
4. Exogenous steroid use The most common cause, from steroid medicines a doctor has prescribed. But the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off does not point to it.
5. Alcohol excess Heavy drinking can copy the Cushing picture, a pseudo-Cushing state. It does not fit the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off.

The point: Cushing syndrome happens when the body has too much cortisol (a stress hormone) for too long. The most common cause by far is taking steroid medicines (glucocorticoids) prescribed by a doctor, so always ask about drug use first. If the cause is inside the body, it depends on a hormone called ACTH. A pituitary tumour that makes too much ACTH is called Cushing disease, and this is the most common cause from inside the body. An adrenal gland tumour or a tumour outside the pituitary that makes ACTH, often a small cell lung cancer, are the other causes. The signs are weight gain around the middle with a round face and a fat pad on the upper back, purple stretch marks (striae), bruising easily, weak muscles near the hips and shoulders (proximal myopathy), high blood pressure, high blood sugar, and thin, weak bones (osteoporosis). First confirm there is too much cortisol, using an overnight dexamethasone suppression test, a 24-hour urine cortisol test, or a late-night saliva cortisol test. Only after that do you check the ACTH level and do a scan to find where the problem is. Treatment is to stop the steroid medicine if possible, or to remove the tumour with surgery. Never stop long-term steroid tablets suddenly. The body's own hormone system has been switched off by the steroids and cannot respond fast enough, so stopping suddenly can cause a dangerous adrenal crisis, the body running out of cortisol.

Source: Therapeutic Guidelines (Australia) — Endocrinology: Cushing syndrome Therapeutic Guidelines (Australia) · tier 3, national formulary

A 42 year old woman has gained weight centrally with a rounded face and a fat pad at the back of her neck, purple abdominal striae, easy bruising and weakness climbing stairs. She has new hypertension and a raised glucose. She takes no regular medication. An overnight dexamethasone suppression test fails to suppress her cortisol. What is the most appropriate next step in management?

1. Withdraw exogenous steroids where possible For the most common cause, lower the steroid dose slowly rather than stopping it suddenly. But the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off does not point to it.
2. Endocrinology referral Refer to the hormone specialist for diagnosis and treatment. That does not match the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off.
3. Manage hypertension, diabetes and osteoporosis Also treat the high blood pressure, high blood sugar and weak bones that come with too much cortisol. It does not fit the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off.
4. Treat an ectopic ACTH source Treat the tumour outside the pituitary that is making ACTH. Here, the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off points elsewhere.
5. Transsphenoidal surgery for a pituitary adenoma correct Correct. If the ACTH level shows the source is a pituitary tumour, removing it through the nose treats Cushing disease.

The point: Cushing syndrome happens when the body has too much cortisol (a stress hormone) for too long. The most common cause by far is taking steroid medicines (glucocorticoids) prescribed by a doctor, so always ask about drug use first. If the cause is inside the body, it depends on a hormone called ACTH. A pituitary tumour that makes too much ACTH is called Cushing disease, and this is the most common cause from inside the body. An adrenal gland tumour or a tumour outside the pituitary that makes ACTH, often a small cell lung cancer, are the other causes. The signs are weight gain around the middle with a round face and a fat pad on the upper back, purple stretch marks (striae), bruising easily, weak muscles near the hips and shoulders (proximal myopathy), high blood pressure, high blood sugar, and thin, weak bones (osteoporosis). First confirm there is too much cortisol, using an overnight dexamethasone suppression test, a 24-hour urine cortisol test, or a late-night saliva cortisol test. Only after that do you check the ACTH level and do a scan to find where the problem is. Treatment is to stop the steroid medicine if possible, or to remove the tumour with surgery. Never stop long-term steroid tablets suddenly. The body's own hormone system has been switched off by the steroids and cannot respond fast enough, so stopping suddenly can cause a dangerous adrenal crisis, the body running out of cortisol.

Source: Therapeutic Guidelines (Australia) — Endocrinology: Cushing syndrome Therapeutic Guidelines (Australia) · tier 3, national formulary

A 42 year old woman has gained weight centrally with a rounded face and a fat pad at the back of her neck, purple abdominal striae, easy bruising and weakness climbing stairs. She has new hypertension and a raised glucose. She takes no regular medication. An overnight dexamethasone suppression test fails to suppress her cortisol. What is the most appropriate definitive management?

1. ACTH level to localise the source correct Correct. Once too much cortisol is confirmed, the ACTH level is checked to find whether the cause is in the pituitary, the adrenal gland, or elsewhere.
2. Do not stop long-term steroids abruptly The body's own hormone system is switched off, so stopping suddenly can cause an adrenal crisis. But the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off does not point to it.
3. Manage hypertension, diabetes and osteoporosis Also treat the high blood pressure, high blood sugar and weak bones that come with too much cortisol. That does not match the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off.
4. Withdraw exogenous steroids where possible For the most common cause, lower the steroid dose slowly rather than stopping it suddenly. Here, the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off points elsewhere.
5. Adrenalectomy for an adrenal tumour Remove the adrenal gland tumour when that is the cause. It does not fit the combination of weight gain around the middle, stretch marks and weak muscles near the hips, with cortisol that fails to switch off.

The point: Cushing syndrome happens when the body has too much cortisol (a stress hormone) for too long. The most common cause by far is taking steroid medicines (glucocorticoids) prescribed by a doctor, so always ask about drug use first. If the cause is inside the body, it depends on a hormone called ACTH. A pituitary tumour that makes too much ACTH is called Cushing disease, and this is the most common cause from inside the body. An adrenal gland tumour or a tumour outside the pituitary that makes ACTH, often a small cell lung cancer, are the other causes. The signs are weight gain around the middle with a round face and a fat pad on the upper back, purple stretch marks (striae), bruising easily, weak muscles near the hips and shoulders (proximal myopathy), high blood pressure, high blood sugar, and thin, weak bones (osteoporosis). First confirm there is too much cortisol, using an overnight dexamethasone suppression test, a 24-hour urine cortisol test, or a late-night saliva cortisol test. Only after that do you check the ACTH level and do a scan to find where the problem is. Treatment is to stop the steroid medicine if possible, or to remove the tumour with surgery. Never stop long-term steroid tablets suddenly. The body's own hormone system has been switched off by the steroids and cannot respond fast enough, so stopping suddenly can cause a dangerous adrenal crisis, the body running out of cortisol.

Source: Therapeutic Guidelines (Australia) — Endocrinology: Cushing syndrome Therapeutic Guidelines (Australia) · tier 3, national formulary