Pituitary disease

Primary = adrenal failure (Addison's disease). Mineralocorticoid AND glucocorticoid insufficiency. Low steroids, low aldosterone, high ACTH (hyperpigmentation), high renin. 

Secondary = ACTH deficiency (pituitary disease). Glucocorticoid insufficiency ONLY. Low steroids, low ACTH, normal aldosterone + renin.

Sx: N+V, hyponatraemia, hyperkalaemia, hypoglycaemia, altered mental status, abdominal pain, salt cravings (primary), hyperpigmentation (primary), orthostatic hypotension, fatigue, wt loss, malaise

Dx: ACTH stimulation test (give ACTH, no cortisol response) then look for cause.

Treatment: replacement glucocorticoids (hydrocortisone 15-30mg, increase dose in illness), replacement mineralocorticoids in primary disease (fludrocortisone 50-300mcg)

Addisonian crisis = decompensated hypoadrenalism, often precipitated by illness injury. Requires IV fluids and steroids (100mg IV hydrocortisone). Most commonly due to withdrawal of steroid treatment. 

Disease- benign ACTH-secreting pituitary adenoma. Raised ACTH, raised cortisol.

Syndrome- exogenous steroids (variable cortisol, low ACTH), ectopic ACTH secretion (high ACTH, high cortisol), benign cortisol-secreting adrenal adenoma (high cortisol, low ACTH).

Sx: hyperglycaemia, moon face, buffalo hump, wt gain, central obesity, muscle wasting, hirsutism, thin skin, easy bruising, amenorrhoea, HTN, insulin resistance, hyperglycaemia, depression, acne, striae, osteoporosis

Dx of disease: 1. Hx- exclude exogenous steroids. 2. Demonstrate high cortisol (urinary free cortisol, midnight serum cortisol). 3. Demonstrate high ACTH (serum ACTH). 4. Dexamethasone suppression test (low dose=cortisol not suppressed, high dose=cortisol suppressed). 5. Localise to pituitary (imaging/inferior petrosal sinus sampling).

Mgmt: treat underlying cause if possible. Pituitary surgery (if not possible or recurrence without surgical target: steroidogenesis inhibitors/pituitary radiotherapy). Steroidogenesis inhibitors/ adrenalectomy.

Primary: thyroid failure (congenital, autoimmune, infection, iatrogenic). Low T3/T4, high TSH. Aim to treat until TSH in normal range.

Secondary: pituitary failure. Low T3/T4, low TSH. Aim to treat until T3 in normal range and T4 at upper end of normal.

Sx: depression, wt gain, constipation, menorrhagia, mental slowness, sensitive to cold, dry skin/ hair, fatigue

Mgmt: levothyroxine

Myxoedema coma: drowsiness, hypothermia, bradycardia. Mgmt with passive rewarming (blankets) and thyroid hormone replacement + admission to HDU for close monitoring.

Primary: thyroid overactivity (autoimmune/Grave's, toxic nodule, toxic multinodular goitre, early De Quervain's, thyroid Ca). High T3/T4, low TSH.

Secondary: TSHoma. High T3/T4, high TSH.

Sx: wt loss, anxiety, tremor, sweating, sensitive to heat, amenorrhoea, diarrhoea, tachycardia, palpitations, goitre, eye Sx (Graves), proximal muscle wasting (Graves), pretibial oedema (graves)

Treatment: antithyroid drugs then thyroid destruction (radioiodine or surgery) followed by lifelong thyroid hormone replacement. Secondary disease- somatostatin/antithyroid drugs then transsphenoidal surgery.

Thyroid storm: decompensation, usually precipitated by illness/injury but can be 1st presentation. Tachycardia, anxiety, hyperpyrexia, HTN, D+V, agitation, may be complicated with HF. Treat with supportive measures (e.g. beta blockers), antithyroid drugs or high dose iodine (Wolff-Chaikoff effect) so they can be made ready for surgery/definitive therapy.

Primary: gonadal failure (autoimmune, infection, trauma/surgery, chemotherapy, drugs, haemochromatosis, congenital). Low sex steroids, high LH/FSH.

Secondary: pituitary failure. Low sex steroids, low LH/FSH.

Male Sx: lack of body/facial hair, erectile dysfunction, infertility, loss of libido, central obesity, osteoporosis

Female Sx: amenorrhoea, infertility, loss of libido, osteoporosis

Mgmt: treat underlying cause, HRT, address infertility if desired

Female Sx: galactorrhoea, menstrual irregularity, infertility

Male Sx: gynaecomastia, often present late, erectile dysfunction, headaches, osteoporosis

Causes: physiological (pregnancy/breastfeeding, stress, sex), drugs (metoclopramide, anti-psychotics, COCP), prolactin-secreting pituitary adenomas, hypothyroidism, cirrhosis, ESRD, chest wall and spinal cord lesions, stalk hyperprolactinaemia, inflammatory (sarcoidosis)

Treatment: dopamine agonists (cabergoline, bromocriptine, quinagolide)

Growth hormone XS

Dx: raised IGF-1, failure to suppress GH levels with oral glucose tolerance test, imaging (macroadenoma)

Sx: large hands and feet, frontal bossing, coarse facial features, organomegaly, visual field defects, impaired glucose tolerance, diabetes, HTN, obstructive sleep apnoea, sweating, carpal tunnel syndrome, osteoarthritis, CVS disease

Mgmt: transsphenoidal surgery, somatostatin analogues, dopamine agonists, pituitary radiotherapy, pegvisomant