Pituitary and Adrenal Disease Flashcards
What are some benign tumours of the pituitary?
Most common = pituitary adenoma
Rare
- Craniopharyngioma
- Meningioma
What are some malignant tumours of the pituitary?
Primary
Metastastic
- Lung
- Breast
Are pituitary cysts common?
No, very rare
What are some cysts of the pituitary?
Rathke’s cleft
Arachnoid
Dermoid
What is lymphocytic hypophysitis?
Inflammation of pituitary gland
Becoming more common
Commonly cases thyroid dysfunction but can affect whole gland
What is a vascular cause of a sellar mass?
Carotid aneurysm
What are the local effects of pituitary tumours?
Tumour stretches dura > headaches + sometimes nausea and vomiting
Rare - hydrocephalus
Tumour compresses nasal retinal fibres > visual field defects
Tumour extends laterally > cranial nerve palsies and temporal lobe epilepsies
Tumour extends downwards > CSF rhinorrhoea
What do you do if you find a non-functioning pituitary adenoma?
Nothing, unless size big enough to cause concern
What is prolactin secretion sensitive to?
Stress
Certain medications; eg:
- Antidepressants
- Atypical antipsychotics
What is the treatment for a prolactinoma?
Dopamine agonists > reduce tumour size and prolactin secretion
- Bromocriptine
- Cabergoline
What pituitary hormones does prolactin suppress?
Gonadotrophins
What are the symptoms of hyperprolactinaemia in females?
Galactorrhoea
Oligomenorrhoea
Headaches
What are the symptoms of hyperprolactinaemia in males?
Gynaecomastia
Infertility
Rarely, galactorrhoea
Testosterone deficiency
If prolactin is raised, what other pituitary hormones are screened?
Full pituitary hormone screen
What are the common causes of acromegaly?
Growth hormone secreting pituitary adenoma
What are the rare causes of acromegaly?
Growth hormone secreting extra pituitary tumour
Growth hormone release hormone (GHRH) secreting tumour
What are the clinical features of acromegaly?
Growth of many tissues
- Skin
- Connective tissue
- Cartilage
- Bone
- Viscera
- Epithelial tissues
- Heart
- Cardiomyopathy
- Arrhythmias
What sort of questions can you ask to determine if it’s acromegaly?
Change in - Shoe size - Glove size - Hat size Compare with previous photos
What affect growth hormone levels?
Diurnal variation
Decreases with food
What are the biochemical results in acromegaly?
Elevated growth hormone
- Failure to suppress with oral glucose tolerance test
Increased IGF1
Diabetes/impaired glucose tolerance
What is the treatment for acromegaly?
1st line: transphenoid hypophysectomy to remove tumour (usually macroadenomas)
If not cured surgically, possible treatments
- Radiotherapy
- Octreotide
- Bromocriptine
What are the ACTH-dependent causes of Cushing’s syndrome?
Cushing’s disease
Ectopic ACTH
Ectopic CRH
What is Cushing’s disease?
ACTH producing tumour - ectopic tumours included
What are the ACTH-independent causes of Cushing’s syndrome?
Adrenal adenoma
Adrenal carcinoma
Micronodular hyperplasia
Macronodular hyperplasia
What are the clinical features of Cushing’s syndrome?
Redistribution of weight centrally Moon face Buffalo hump Wasting of buttocks Atrophy of epidermis > thin skin Plethoric face Easy bruising Striae Depressed mood and crying Decreased concentration and memory Insomnia Decreased libido Proximal myopathy Osteopaenia > crush fractures of vertebrae Glucose intolerance (75%)/diabetes (25%) Hirsutism HTN Menstrual disorders
Why is the administration of corticosteroids avoided in the evening?
Causes insomnia
What are the investigations in Cushing’s syndrome?
FBE
- Hb = high normal range
- WCC = slightly elevated; decreased neutrophils
Electrolytes
- Hypokalaemia and metabolic alkalosis in ectopic ACTH
Insulin resistance > hyperglycaemia
Increased Ca absorption and hypercalciuria
What are the tests used to diagnose Cushing’s syndrome?
Midnight salivary cortisol test 24 hour urine free cortisol Overnight dexamethasone suppression test - 1 mg of dexamethasone at 0000 - Serum cortisol at 0800
How do you interpret the results of an overnight dexamethasone suppression test?
ACTH
- Suppressed > likely adrenal cause
- Normal/slightly elevated > likely pituitary dependent
- Very high > likely ectopic ACTH
What is the treatment for pituitary-dependent Cushing’s syndrome?
Transphenoid hypophysectomy to remove tumour
What is the treatment for an adrenal adenoma or carcinoma?
Adrenal surgery
What is the treatment for ectopic ACTH production or increased CRH production?
Treat tumour associated with hormone production
What can cause adrenocortical insufficiency?
Insufficient secretion of ACTH = hypopituitarism
Destruction of adrenal glands = Addison’s disease
What are the clinical features of Addison’s disease?
Hyperpigmentation
Non-specific symptoms; eg: lethargy
What can cause Addison’s disease?
Autoimmune atrophy Infections Infiltration of metastases Haemorrhage/infarction Drugs Adrenoleukodystrophy
What are the investigation results in Addison’s disease?
Electrolytes - Hyponatraemia - Hyperkalaemia - Moderate acidosis - Increased urea Hypoglycaemia
What are the diagnostic tests for Addison’s disease?
Low serum cortisol High ACTH Synacthen test Adrenal Abs Adrenal imaging - Calcification - Enlargement
How can Addison’s disease present in a medical emergency?
Nausea
Vomiting
Hypovolaemic shock
What is the acute management for an Addisonian crisis?
Hydrocortisone 100 mg IV 6 hrly
IV saline
Glucose if hypoglycaemic
What is the long-term management of Addison’s disease?
Cortisone acetate/hydrocortisone
If also deficient in mineralocorticoids: fludrocortisone
Medic alert
Advice on increasing steroid dose in times of stress and infection
What adrenal diseases can cause an excess of hormone production?
Conn’s syndrome = aldosterone excess
Phaeochromocytoma = catecholamine excess
When may you suspect Conn’s syndrome?
Refractive HTN
Hypokalaemia, even if low normal
What are the subtypes of primary aldosteronism?
Most common = unilateral aldosterone producing adenoma
Bilateral idiopathic hyperaldosteronism
Glucocorticoid suppressible hyperaldosteronism
Aldosterone producing adrenal carcinoma
What is the clinical triad of primary aldosteronism?
HTN Hypokalaemia - Headaches - Palpitations - Polydipsia - Polyuria - Nocturia Metabolic alkalosis
What is the diagnostic approach to primary aldosteronism?
24 hr urine collection to document inappropriate K wasting in presence of hypokalaemia
Plasma renin activity - suppressed
Plasma/urine aldosterone - increased
Increased aldosterone-to-renin ratio
Aldosterone fails to suppress after infusion of 2 L of saline over 4 hrs (=saline suppression test)/high Na intake for 3 days
How is primary aldosteronism localised using imaging?
CT/MRI
131-I-iodocholesterol scanning
Adrenal vein sampling for aldosterone
What is the treatment for primary aldosteronism?
Adrenal adenoma - adrenal surgery
Spironolactone = competitive antagonist to aldosterone
Amiloride = blocks Na channels in proximal tubule > decreases K excretion
What is phaeochromocytoma?
Tumour of chromaffin cells in adrenal medulla
Derived from neural crest cells
What are the clinical features of phaeochromocytoma?
Episodic symptoms - Sudden and severe (<15 min) - Spontaneous/due to - Exercise - Bending over - Defecation - Abdominal pressure - Drugs Paroxysms - Pallor - Perspiration - Palpitations - (Labile blood) pressure > headache Accelerated HTN Supra-renal masses Rarely hypotension Tachyarrhythmias
How is phaeochromocytoma diagnosed?
24 hour urine chatecholamines Plasma catecholamines - marked variability Plasma metanephrines = breakdown products of catecholamines - More sensitive and specific Localise tumour - CT of chest and pelvis - MIBG scanning - Octreotide scanning - Venous sampling for lateralisation
What is the pre-operative treatment of phaeochromocytoma?
Alpha adrenergic blockade - phenoxybenamine
Beta blockers if necessary, but never before alpha blockade
Treatment, as required of
- Arrhythmias
- Cardiac failure
- Diabetes
What is polyglandular autoimmune syndrome type 1?
Autosomal recessive disorder
Very rare
Mutation in AIRE gene on chromosome 21
What are the endocrine effects of polyglandular autoimmune syndrome type 1?
Hypoparathyroidism Chronic mucocutaneous candidiasis Adrenal insufficiency Primary hypogonadism Hypothyroidism T1D Hypothyroidism Hypopituitarism Diabetes insipidus
What are the non-endocrine effects of polyglandular autoimmune syndrome type 1?
Malabsorption syndromes Alopecia totalis/areata Pernicious anaemia Chronic active hepatitis Vitiligo
What is polyglandular autoimmune syndrome type 2?
More common than type 1 More than 50% familial Inheritance - Autosomal recessive - Autosomal dominant - Polygenic Associated with high Ab titres to steroid producing cells - Adrenals - Thyroid - Testis/ovary
What are the endocrine effects of polyglandular autoimmune syndrome type 2?
Adrenal insufficiency Autoimmune thyroid disease T1D Primary hypogonadism Diabetes insipidus
What are the non-endocrine effects of polyglandular autoimmune syndrome type 2?
Vitiligo Alopecia Pernicious anaemia Myaesthenia gravis Immune thrombocytopenic purpura Sjogrens syndromes Rheumatoid arthritis
Where is the MEN1 gene located?
Chromosome 11
What is the inheritance pattern of MEN1 syndrome?
Autosomal dominant
What is the triad of tumours in MEN1 tumours?
Pituitary
Pancreas
Parathyroid
What is the inheritance pattern of MEN2 syndrome?
Autosomal dominant
What causes MEN2 syndrome?
Mutations of RET proto-oncogene on chromosome 10
What are the tumours in MEN2a syndrome?
Medullary carcinoma of thyroid
Phaeochromocytoma
Parathyroid hyperplasia
What are the tumours of MEN2b syndrome?
Medullary carcinoma of thyroid Phaeochromocytoma Parathyroid hyperplasia Mucosal neuromas Intestinal ganglioneuromas Marfanoid habitus
