Endocrinology Flashcards
(111 cards)
1
Q
What is acromegaly?
A
Excessive secretion of growth hormone in patients who have passed puberty
2
Q
What is the condition called when there is excess growth hormone in children?
A
Gigantism
3
Q
Where is GH secreted from?
A
Anterior pituitary
4
Q
What regulates GH secretion?
A
Growth hormone releasing hormone (GHRH)
Somatostatin (inhibits GH)
5
Q
Where is GH releasing hormone secreted from?
A
Hypothalamus
6
Q
What is the function of GH?
A
Indirectly stimulating soft tissue and bone growth through the use of insulin-like growth factor 1 (IGF-1)
7
Q
What is the main cause of acromegaly?
A
Pituitary tumour
8
Q
What are the symptoms of acromegaly?
A
Sweating Headaches Increasing size of hands and feet Amenorrhea Infertility Muscle weakness Enlarged tongue Increased dental spacing Hoarse voice Prominent lower jaw
9
Q
What test is done to diagnose acromegaly?
A
Oral glucose tolerance test
Glucose should inhibit GH secretion so after glucose GH levels should be undetectable. In acromegaly there is a failure to suppress GH.
10
Q
What is the first line treatment of acromegaly?
A
Surgical removal of pituitary tumour
11
Q
What nonsurgical treatments can be given to treat acromegaly?
A
Somatostatin analogues
Radiotherapy
12
Q
Give 3 potential complications of acromegaly
A
Bitemporal hemianopia Carpal tunnel Diabetes Hypertension Osteoporosis Obstructive sleep apnea
13
Q
What is Cushing’s Syndrome?
A
Excess cortisol in the blood
14
Q
What is the main cause of Cushing’s syndrome?
A
Too much steroid medication (iatrogenic)
15
Q
What is Cushing’s disease?
A
Excess cortisol due to a pituitary adenoma releasing excess ACTH.
ACTH dependent
16
Q
Name the 3 sources that may cause excess cortisol in the body
A
Pituitary tumour
Adrenal tumour
ACTH-secreting Ectopic tumour
17
Q
Which 4 cancers can ectopically secrete ACTH?
A
Small cell lung tumour
Thymus gland tumours
Islet cell tumours of the pancreas
Medullary carcinoma of the thyroid
18
Q
Give 5 symptoms of Cushing’s
A
Weight gain centrally Depression Insomnia Amenorrhea Thin skin Easy bruising Stretch marks Acne Back pain Excessive hair growth (women) Polyuria
19
Q
Give 5 signs of Cushing’s
A
Moon face Osteoporosis Proximal myopathy Increased pigmentation Kyphosis Buffalo hump Oedema
20
Q
Why may a woman with Cushings have signs of hirsutism?
A
Excess ACTH stimulates excess testosterone to be released from the adrenal glands as well as excess cortisol
21
Q
What condition is very commonly associated with Cushing’s?
A
Type II diabetes
22
Q
How does the dexamethasone suppression test diagnose Cushing’s?
A
Give the patient a dexamethasone tablet. Dexamethasone should suppress ACTH release from the pituitary. The following morning test serum cortisol levels. If cortisol is still high then Cushing’s disease is diagnosed
23
Q
How can the cause of Cushing’s be established from the dexamethasone suppression test?
A
Pituitary tumour –> at low dose high cortisol, high ACTH. At high dose, decreased cortisol
Ectopic tumour –> at low dose high cortisol, high ACTH. At high dose, high cortisol
Adrenal tumour –> at low dose high cortisol, low ACTH
24
Q
Why are stand alone cortisol readings unrepresentative of Cushing’s disease?
A
Cortisol levels are cyclical and so readings cannot be compared against a standard.
25
How is Cushing's disease treated?
Surgical removal of the tumour
| Decrease steroid medication
26
What is Primary Hypoadrenalism (Addison's disease)?
Destruction of the adrenal cortex which results in a lack of secretion of cortisol, aldosterone and the sex hormones
27
What are the two main causes of Addison's?
Autoimmune reaction
| TB infection
28
Give 5 symptoms of Addison's disease
```
Fatigue
Weight loss
Anorexia
Myalgia
Dizziness
Fainting
Low self esteem
Depression
Skin pigmentation
```
29
What happens to sodium levels in Addison's?
Decrease
30
What is an Addisonian crisis?
Severe hypotension and dehydration following trauma or an illness.
31
How is an Addisonian crisis treated?
Emergency cortisol
| Sodium infusion
32
What tests can be done to help diagnose Addison's disease?
U&Es, glucose, adrenal antibodies, FBC, Serum aldosterone, chest and abdo x-ray
33
Describe the ACTH stimulation test
Given synthetic ACTH to stimulate cortisol production. Cortisol should rise rapidly to >550 nmol/L but in Addison's it will not
34
How is Addison's managed in the long term?
Oral hydrocortisone
Monitor BP and serum electrolytes and weight
Educate patient on effects of long-term steroid use
35
When does secondary hypoadrenalism occur?
Secondary hypoadrenalism occurs when a patient has been taking long-term steroids and they suddenly stop them. The HPA axis has been suppressed due to the ectopic source of cortisol so when the patient suddenly stops the body cannot quickly adjust to making enough cortisol on its own.
36
In secondary hypoadrenalism, why is aldosterone secretion not affected?
Stimulation from angiotensin II
37
What happens to the aldosterone level in primary and secondary hypoaldosteronism?
```
Primary = high
Secondary = low
```
38
How is secondary hypoaldosteronism treated?
Restart steroids and gradually reduce rather than come off in one go
If pituitary disease, can give synthetic ACTH
39
What is hyperthyroidism?
Excess thyroid hormone in the blood.
40
What is the epidemiology of hyperthyroidism?
Women more affected
| Ages 20 to 40
41
What is Grave's disease?
Autoimmune condition where antibodies are produced for the TSH receptor which stimulate more TSH to be produced. The TSH then creates more T3 and T4.
42
What are the two most common causes of nodular thyroid disease?
Iodine excess in the diet
| Medications such as Amiodarone
43
Give 5 symptoms of hyperthyroidism
```
Weight loss
Hyperactivity
Palpitations
Fatigue
Weakness
Diarrhoea
Polyuria
Menorrhagia
Fine tremor
Intolerance to warmth
Gynaecomastia
Proptosis
Clubbing
Goitre
```
44
What is a thyrotoxic storm?
Undertreated hyperthyroidism
Fever, seizures, vomiting, diarrhoea, jaundice, arrhythmias, heart failure, hyperthermia
45
How is a thyroid storm treated?
Propranolol
Antithyroid drugs
Potassium iodide
Corticosteroids
46
How is hyperthyroidism treated?
Propranolol (symptom control)
Radioiodine
Carbimazole (risk of agranulocytosis)
47
What is hypothyroidism?
Thyroid does not produce enough thyroid hormone
48
Give 3 ways hypothyroidism can occur
Autoimmune destruction
Excessive treatment of hyperthyroidism
Iodine deficiency
49
What is atrophic hypothyroidism?
T-cell mediated cytotoxicity against follicular cells in the thyroid
50
What is hashimoto's disease?
Thyroid attacked by T-cells which causes a goitre to form due to infiltration of the thyroid with lymphocytes resulting in fibrosis.
51
What are the symptoms of hypothyroidism?
```
Tiredness
Weight gain
Cold intolerance
Poor appetite
Depression
Thin hair
Constipation
Dry skin
Hypertension
Hypothermia
Bradycardia
```
52
What investigations will be done for hypothyroidism?
```
FBC
U&Es
Cholesterol
TSH
T3/4
```
53
How is hypothyroidism treated?
Levothyroxine
54
What is Conn's Syndrome?
Type of primary hyperaldosteronism from an aldosterone-producing adenoma
55
What are the symptoms of Conn's syndrome?
Often asymptomatic
| Can have weakness, cramps, polyuria, polydipsia
56
How is Conn's syndrome treated?
Laparoscopic adrenalectomy
| Spironolactone
57
What is diabetes insipidus?
Reduced ADH secretion from the posterior pituitary causing the passage of large amounts of dilute urine.
58
What happens to sodium and potassium levels in diabetes insipidus?
Hypokalaemia
| Hypernatraemia
59
What are the symptoms of diabetes insipidus?
Polyuria
Polydipsia
Dehydration
Symptoms of hypokalaemia and hypernatraemia
60
What are the causes of a lack of ADH production?
```
Hypothalamus disease
Pituitary disorder
Neurosurgery
Trauma
Idiopathic
Sarcoidosis
```
61
How is diabetes insipidus treated?
Identify and treat the cause
| Give desmopressin which is synthetic ADH
62
What is SIADH?
Excessive ADH secretion from the posterior pituitary gland or another ectopic source.
63
Why does SIADH result in hyponatremia?
The level of sodium in the blood stays the same but because the blood fluid increases there is a dilutional hyponatraemia
64
What is the pathophysiology of SIADH?
ADH acts on the DCT and collecting duct to reabsorb water and dilute the blood. When ADH secretion is not suppressed excessive water is reabsorbed back into the blood
65
Give 5 potential causes of SIADH
```
Small cell lung tumour
Meningitis
Head injury
TB
Alcohol withdrawal
Opiates
Hypothyroidism
```
66
What are the clinical features of SIADH?
```
Nausea
Myalgia
Irritability
Headache
Cheyne-Stokes respiration
```
67
What is Cheyne-Stokes respiration?
Repeating cycles of deep and fast breathing followed by apnoea
68
How is SIADH diagnosed?
Euvolemic hyponatremia
Low serum sodium
High urine sodium
Low plasma osmolality
Absence of hypokalemia, hypotension and hypovolemia
Normal renal, adrenal and thyroid function
69
How is SIADH treated?
Treat underlying cause
Water restriction
Demeclocycline (inhibits action of ADH)
Tolvaptan (treats hyponatremia)
70
What is a microadenoma?
Pituitary tumour which is <1 cm across
71
What is a macroadenoma?
Pituitary tumour which is >1 cm across
72
What are the 3 histological types of pituitary tumour?
Chromophobe --> mostly non-secreting
Acidophil --> secrete GH or prolactin
Basophil --> secrete ACTH
73
What are the symptoms from a pituitary tumour?
Caused by raised intracranial pressure or from the abnormal pituitary secretions
Headaches, visual field defects, anopia, CN III, IV, VI palsy
74
What investigations are done if a pituitary tumour is suspected?
LH, FSH, Testosterone, TSH, T4, Prolactin, IGF-1, cortisol, U&Es, FBC, short synACTHen test, insulin tolerance test, MRI of pituitary
75
How is a pituitary tumour treated?
Hormone replacement
Transsphenoidal surgery to remove tumour
Radiotherapy
76
What is hypopituitarism?
Reduced secretion of pituitary hormones
77
In which order are pituitary hormones affected in hypopituitarism?
GH --> FSH --> LH --> prolactin --> TSH --> ACTH
78
Why may panhypopituitarism occur?
Irradiation
Surgery
Large tumour
79
In what situations will oxytocin and vasopressin be affected in hypopituitarism?
If the hypothalamus is affected as well
80
Give 3 hypothalamic causes of hypopituitarism
```
Kallmann's syndrome
Tumour
Inflammation
Infection (TB/meningitis)
Ischaemia
```
81
Give 3 pituitary stalk causes of hypopituitarism
```
Trauma
Surgery
Mass lesion
Meningioma
Carotid artery aneurysm
```
82
Give 3 pituitary causes of hypopituitarism
```
Tumour
Irradiation
Autoimmunity
Inflammation
Infiltration
Ischaemia
```
83
How is hypopituitarism treated?
```
Oral replacement of steroids and thyroid hormones
LH and FSH analogues
Testogel to replace testosterone
Oestrogen if premenopausal
GH therapy in children
```
84
What is the main cause of primary hyperparathyroidism?
Adenoma of the parathyroid gland
85
How does hyperparathyroidism present?
Weakness, depression, tiredness, thirst, abdominal pain, bone pain, fractures
86
How is hyperparathyroidism diagnosed?
```
Serum calcium
Serum PTH
Phosphate
LFTs
X-ray
DEXA scan for osteoporosis
```
87
How is hyperparathyroidism managed?
Increase fluid intake
Avoid thiazide diuretics
Remove tumour
88
What is the main cause of secondary hyperparathyroidism?
Chronic renal failure
| Vitamin D deficiency
89
What 3 cancers can ectopically secrete parathyroid hormone?
Squamous cell lung tumour
Breast cancer
Renal cell carcinoma
90
What are the main causes of hypoparathyroidism?
Autoimmune destruction
| DiGeorge syndrome
91
How is hypoparathyroidism treated?
Ca2+ supplements
Calcitriol
Synthetic PTH
92
How is hypoparathyroidism diagnosed?
Serum PTH
Calcium
Phosphate
LFTs
93
What is hyperprolactinemia?
Excess prolactin present in the blood
94
Give 4 reasons for hyperprolactinaemia
Pregnancy (physiological)
Pituitary prolactinoma
Pituitary stalk compression (causing reduced dopamine)
Drugs- metoclopramide, haloperidol, oestrogens
95
What are the symptoms of hyperprolactinemia?
Amenorrhoea, infertility, galactorrhea, weight gain, loss of libido, erectile dysfunction, loss of facial hair
96
How is hyperprolactinemia treated?
```
Dopamine agonists (bromocriptine)
Removal of tumour
```
97
What is pheochromocytoma?
Neuroendocrine tumour of the medulla of the adrenal glands which secretes large amounts of noradrenaline and adrenaline
98
How does pheochromocytoma present?
```
Headaches
Hypertension
Tachyarrhythmias
Flushing
Weight loss
Malaise
Sweating
Pallor
Hyperglycaemia
Pyrexia
Abdominal pain
```
99
Give 4 complications of pheochromocytoma
```
MI
Heart failure
Cardiomyopathy
Arrhythmias
Stroke
Coma
Death
```
100
How is pheochromocytoma diagnosed?
Metadrenaline levels
24hr urine collection of catecholamines
CT abdomen
101
How is pheochromocytoma treated?
Alpha-blockers
Beta-blockers
Surgical resection of adrenal gland
102
What is the karyotype in Turner's patients?
(45,X)
103
What are the features of Turner's syndrome?
Short, underdeveloped ovaries, lack of periods, infertility, webbed neck, low hairline, spoon-shaped nails
104
Name 3 conditions Turner's syndrome is associated with
```
Heart murmurs
UTIs
Hypothyroidism
Hypertension
Osteoporosis
Scoliosis
Diabetes
Crohn's
UC
```
105
What is the karyotype in Klinefelter's patients?
(47,XXY)
106
What are the features of Klinefelter's syndrome?
Tall, lack of secondary sexual characteristics, small testes, infertile, gynaecomastia, elevated gonadotropin levels
107
What is Multiple Endocrine Neoplasia (MEN)?
The occurrence of several functional tumours in multiple endocrine glands. The glands involved all have a similar embryological origin.
108
What are the features of MEN Type 1?
Presents in 30-50s
Parathyroid hyperplasia
Pancreatic tumours
Anterior pituitary tumours (prolactinoma or acromegaly)
May also get carcinoid syndrome (flushing, diarrhoea, palpitations, hypotension and right sided heart failure)
109
What are the features of MEN Type 2a?
Medullary thyroid carcinoma
Adrenal pheochromocytoma (bilateral)
Parathyroid hyperplasia
110
What are the features of MEN Type 2b?
Medullary thyroid carcinoma
Adrenal pheochromocytoma (bilateral)
Hyperplasia of autonomic ganglia in the intestinal wall
Mucosal neuromas on lips, cheek, tongue and glottis
111
How is MEN managed?
Removal of the tumours surgically
Treatment of symptoms as they present
Screen family members due to autosomal dominant inheritance
Ongoing surveillance to detect new tumours early
