Endocrine Pathophysiology - The Adrenal Gland and Acromegaly Flashcards
What is Cushing’s syndrome?
A collection of signs and symptoms that occur when a patient has long term exposure to cortisol
Causes of Cushing’s syndrome
Exogenous
- Iatrogenic eg prescription of glucocorticoids for asthma
Endogenous
- ACTH dependent
- Cushing’s disease (ACTH is prosuced from a pituitary adenoma)
- Ectopic ACTH production (usually from small cell lung cancer)
- ACTH independent: CARS
- Cancer: adrenal carcinoma
- Adrenal nodular hyperplasia
- Rare causes: McCune-Albright syndrome
- Steroid use
Signs and symptoms of Cushing’s syndrome
Round in the middle with thin limbs:
- Round “moon” face
- Central Obesity
- Abdominal striae
- Cervical fat pad
- Proximal limb muscle wasting
High levels of stress hormone:
- Hypertension
- Cardiac hypertrophy
- Hyperglycaemia (Type 2 Diabetes)
- Depression
- Insomnia
- Acne
- Amenorrhoea
Extra effects:
- Osteoporosis
- Easy bruising and poor skin healing
Cushing’s syndrome investigations
- Diagnostic tests: urinary free cortisol, low does and high dose dexamethasone suppression test
- Bloods: FBC, U&Es, LFTs, glucose, lipid levels
- Radiology: XR (look for lung cancer and vertebral collapse)
- DEXA (dual energy X-ray) scan
Cushing’s syndrome treatment
- Conservative
- Advise patients to decrease alcohol consumption since alcohol increases cortisol levels
- Medical
- Ketoconazole, metyrapone, fluconazole to decrease cortisol
- Treat compications
- Surgical (main treatment)
- Trans-sphenoidal removal of pituitary adenoma
- Surgical removal of adrenal tumour
- Surgical removal of tumour producing ectopic ACTH
If surgical removal of the cause is not possible another option is to remove both adrenal glands and give the patient replacement steroid hormones for life.
Cushing’s syndrome complications
- Osteoporosis
- Diabetes mellitus
- Hypertension
- Immunosupression
- Cataracts
- Striae formation
- Ulcers
What is adrenal insufficiency?
Occurs when the adrenal glands fail to produce sufficient steroid hormone
Causes of primary adrenal insufficiency
- Primary
- Addison’s disease
- Idiopathic
- Postadrenalectomy
- Secondary
- Prolonged prednisolone use
- Pituitary adenoma
- Sheehan’s syndrome
Causes of Addison’s disease
- Metastases from breast, lung and renal cancers
- Autoimmune
- Infections
- Lymphomas
Signs and symptoms of adrenal insufficiency
- Unintentional weight loss
- Myalgia
- Weakness
- Fatigue
- Postural hypertension
- Skin pigmentation
- Body hair loss
- Abdominal pain
- Diarrhoea
- Nausea and vomiting
- Deprssion
Adrenal insufficiency investigations
- Diagnostic tests
- Adrenocorticotropic hormone (ACTH) and cortisol measurements
- Insulin tolerance test
- Short Synacthen test
- Bloods: FBC, U&Es (↓Na+, ↑K+), LFTs, gucose, lipid levels, serum calcium
- Radiology
- CXR (look for lung cancer)
- CT and MRI scan of the adrenal glands
Adrenal insufficiency treatment
- Conservative
- Patient must carry a steroid alert card
- Medical
- Replace glucocorticoids and mineralocorticoids with hydrocortisone and fludocortisone
- Treat complications
- Surgery
- Surgical excision of tumour if indicated
Complications of adrenal insufficiency
- Adrenal crisis
- Hyperkalaemia
- Hypoglycaemia
- Eosinophilia
- Alopecia
Addison’s disease is associated with which conditions?
3PGH
- Pernicious anaemia
- Primary ovarian failure
- Polyglandular syndrome
- Grave’s disease
- Hashimoto’s thyroiditis
What is acromegaly?
Acromegaly is a syndrome that results from excessive growth hormone production after fusion of the epiphyseal plates. Excess GH prosuced before epiphyseal plate fusion causes gigantisism.
