Endocrinology III Flashcards Preview

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Flashcards in Endocrinology III Deck (77):
1

Causes of impotence
A Addison's disease
B Drug induced
C Haemochromatosis
D Klinefelter's syndrome
E Non-functioning pituitary tumour
F Primary gonadal failure
G Prolactinoma
H Psychological
I Thyrotoxicosis
J Vascular

Select the most likely diagnosis for the following patients presenting with impotence.
Normal ranges:
Testosterone 10-30 nmol/L
LH 1-10 mu/L
FSH 1-10 mu/L
Prolactin 100-500 mu/L
A 62-year-old male presents concerned regarding impotence. His wife of 30 years died three years ago and he found a partner six months ago but has been unable to have intercourse due to erectile dysfunction. He is treated for agitated depression and has been prescribed risperidone.
His results show:

Testosterone 8.8 nmol/l
LH 2.1 mu/l
FSH 3 mu/l
Prolactin 850 mu/l

Drug induced
There are numerous causes of drug induced impotence. In this case, risperidone, a dopaminergic antagonist, is associated with hyperprolactinaemia and can produce hypogonadotrophic hypogonadism as a consequence.

2

Causes of impotence
A Addison's disease
B Drug induced
C Haemochromatosis
D Klinefelter's syndrome
E Non-functioning pituitary tumour
F Primary gonadal failure
G Prolactinoma
H Psychological
I Thyrotoxicosis
J Vascular
Select the most likely diagnosis for the following patients presenting with impotence.
Normal ranges:
Testosterone 10-30 nmol/L
LH 1-10 mu/L
FSH 1-10 mu/L
Prolactin 100-500 mu/L

An 18-year-old male presents with concerns over impotence and reduced libido. He has recently entered into his first relationship with a woman and is concerned by his poor penile development, unaware of any erections and little sex drive. On inspection you note that he is tall and has little facial hair.
Results show:
Testosterone 7 nmol/l
LH 22 mu/l
FSH 33 mu/l
Prolactin 255 mu/l

Klinefelter's syndrome is associated with XXY karyotype and is associated with elevated LH/FSH and low testosterone.

Although associated with primary gonadal failure it is important to recognise Klinefelter's as causing the former and the features include:

the poor pubertal development
lack of shaving
tall stature
often poor school performance (Klinefelter's is associated with lower IQ).
Treatment is with testosterone replacement.

It is highly likely that he will be infertile.

3

Endocrine disorders
A ACTH producing tumour
B Hyperaldosteronism
C MEN 1
D MEN 2a
E MEN 2b
The following patients have all presented with endocrine disorders.
Please choose the most appropriate answers from the given list.
Hyperprolactinaemia and gastric ulcers

MEN 1
The multiple endocrine neoplasia syndromes are characterised by tumours involving two or more endocrine glands. Their inheritance is autosomal-dominant or sporadic.

MEN 1 is characterised by anterior pituitary adenoma, pancreatic tumours (gastrinomas, insulinomas) and parathyroid hyperplasia.

4

Endocrine disorders
A ACTH producing tumour
B Hyperaldosteronism
C MEN 1
D MEN 2a
E MEN 2b
The following patients have all presented with endocrine disorders.
Please choose the most appropriate answers from the given list.

Hypertension, neck lump and tachycardia

MEN 2a

Multiple endocrine neoplasia 2 describes the association of medullary thyroid carcinoma, phaeochromocytomas and thyroid tumours.

MEN 2 is subdivided into 2a, 2b and medullary thyroid carcinoma only:

MEN 2a is the most common variant with parathyroid disease commonly following the development of medullary thyroid cancer, 50% of patients develop phaeochromocytomas.

MEN 2b is characterised by medullary thyroid carcinoma, parathyroid hyperplasia, phaeochromocytoma, marfanoid features and mucosal neuromas. In MEN 2b, the medullary cancer is very aggressive with most patients dying before developing either a phaeochromocytoma or hyperparathyroidism.

5

Endocrine disorders
A ACTH producing tumour
B Hyperaldosteronism
C MEN 1
D MEN 2a
E MEN 2b
The following patients have all presented with endocrine disorders.
Please choose the most appropriate answers from the given list.


Hypokalaemia and alkalosis

Primary hyperaldosteronism results from excessive secretion of aldosterone by an adenoma of the adrenal cortex. Aldosterone causes retention of sodium in exchange for potassium and hydrogen in the distal nephron, resulting in hypokalaemic alkalosis and hypertension due to intravascular fluid expansion secondary to sodium retention.

Patients may also report

Muscle weakness
Cramps
Polydipsia
Polyuria.

6

Homeostatis: Hormones involved in homeostatic control
A ACTH
B CRH
C Dopamine
D FSH
E GnRH
F Growth hormone
G LH
H Prolactin
I Somatostatin
J TSH
From the options, please select the correct hormone for each of the descriptions below.
You may use each option once, more than once, or not at all.
This hormone acts on cartilage and liver to release IGF-1.

This hormone promotes iodination of tyrosine residues.

This hypothalamic hormone inhibits the secretion of growth hormone.

In males, this hormone facilitates the generation of spermatozoa.

This hormone inhibits galactorrhoea.

Growth hormone acts on the liver to release IGF-1. IGF-1 then acts on cells around the body, especially cells in the growth plates of the long bones to grow and divide.

TSH acts on the thyroid gland to iodinate tyrosine residues, to produce thyroxine.

This hypothalamic hormone inhibits the secretion of growth hormone.

Somatostatin
Somatostatin has an important role by inhibiting the secretion of growth hormone.

In males, FSH causes generation of spermatozoa, where LH causes the secretion of testosterone from the testes.

This hormone inhibits galactorrhoea.

Dopamine
Dopamine inhibits galactorrhoea, and hence can be used as a treatment.

7

Which of the following is true of adrenocorticotropic hormone (ACTH)?
(Please select 1 option)
Is increased in the maternal plasma in pregnancy
Is not present in the placenta
Production is governed by the pituitary
Production is maximal about midnight
Secretion is inhibited by mineralocorticoids

Is increased in the maternal plasma in pregnancy

The production of ACTH is governed through the secretion of corticotropin-releasing hormone from the hypothalamic nuclei.

It governs cortisol secretion where cortisol is secreted maximally in the morning and concentrations are at a nadir at midnight.

ACTH can be expressed in numerous tissues besides the pituitary and including the placenta.

ACTH concentrations rise in stress, disease and in pregnancy.

Through negative feedback, glucocorticoids (not mineralocorticoids - aldosterone) switch off ACTH production.

8

n which of the following circumstances does the release of catecholamines from the adrenal medulla increase?
(Please select 1 option)
Approximately one hour following a myocardial infarction
During sleep in healthy individuals
Following an increase in blood sugar
In acute haemorrhage once hypertension develops
When the nerves to the adrenal gland are stimulated

Catecholamine release is generated by:

Stress (i.e. waking)
Sympathetic stimulation (flight, fright, fight response)
During hypoglycaemia (as response to stressful stimuli and counteraction of catecholamines in recruiting glucose)
During illness (e.g. MI, sepsis), and
Hypotensive episodes.

9

Which of the following is true of the anterior pituitary gland?

Exhibits a constant hormone secretion activity
Is connected to the thalamus by neural tissue
Is contained in the anterior cranial fossa
Produces glycoproteins
Produces hormones which share a common beta sub-unit

Glycoproteins

The pituitary stalk connects the anterior pituitary to the hypothalamus and it is contained in the pituitary sella with the optic chiasm and hypothalamus as superior relations.

Glycoproteins such as thyroid-stimulating hormone (TSH) and luteinising hormone (LH) follicle-stimulating hormone (FSH) are produced by the anterior pituitary. These share a common alpha subunit with unique beta subunits.

There is diurnal variation in the secretion of many hormones such as LH, adrenocorticotropic hormone (ACTH) and growth hormone (GH).

10

Which of the following is true regarding thyroid hormones?
(Please select 1 option)
D-thyroxine is more active than L-thyroxine
Starvation causes plasma T3 to rise
T4 acts more rapidly than T3
Thyroid binding globulin (TBG) is increased in pregnancy
Triiodothyronine (T3) is converted in the tissues to thyroxine (T4)
T3 is the major active thyroid hormone but the majority is produced via peripheral de-iodination of T4.

Thyroid binding globulin (TBG) is increased in pregnancy

Most binding proteins, including TBG, are increased in pregnancy and therefore it is much more important to measure free thyroid hormone concentrations than total.

Illness and starvation produce a decline in both T4 and T3 concentrations.

The isomer D-T4 is inactive, it is L-T4 that is the active molecule.

11

Which of the following is untrue of the thyroid gland?
(Please select 1 option)
Actively traps inorganic iodine from plasma
Enlarges during normal pregnancy
Functions from the twelfth week of fetal development
Is stimulated by posterior pituitary hormones
Stores colloid outside epithelial cells

Is stimulated by posterior pituitary hormones

Thyroid hormone production is stimulated by the anterior pituitary hormone (thyroid stimulating hormone [TSH]), and secretion begins from approximately the twelfth week of gestation. The foetus remains dependent on maternal thyroid hormones until about 20 weeks.

Triiodothyronine (T3) and thyroxine (T4) are manufactured within the thyroid cells through iodination of tyrosine. The synthesised T3 and T4 are then stored within the colloid at the centre of the thyroid follicles.

In the mother the thyroid, like most other endocrine organs, moderately enlarges during pregnancy.

12

Which of the following is correct regarding the adrenal glands?
(Please select 1 option)
Cortices contain chromaffin cells
Lie posteriorly to the diaphragm
Lymphatic drainage is to the superficial inguinal nodes
Medulla is derived from mesoderm
On the left lies behind the pancreas

On the left lies behind the pancreas

They are contained within the same membrane as the kidney but separated from them by a fibrous layer of tissue.

The right gland is tetrahedral in shape and lies lower than the left, which is semilunar in shape and usually the larger of the two. Each gland weighs approximately 5 grams and measures approximately 50 mm vertically, 30 mm across and 10 mm thick.

The right lies between the diaphragm posteriorly and the IVC anteromedially. Superiorly lies the bare area of the liver. Its inferior end is covered by peritoneum reflected over it from the liver.

The left lies in the stomach bed, with anterior relations of the stomach and pancreas and posteriorly with the diaphragm. Its inferior part is not covered by peritoneum as it is crossed anteriorly by the tail of the pancreas and splenic vessels.

The adrenal medulla contains the chromaffin cells.

Embryologically the medulla is derived from neural crest cells and cortex from mesoderm.

13

Which of the following is correct of prolactin (PRL)-secreting pituitary tumours?
(Please select 1 option)
Are usually macroadenomas at presentation
Produce homonymous hemianopia with a suprasellar extension
Regress during pregnancy
Suprasellar extension is an indication for immediate surgical intervention
Tend to cause higher prolactin levels than idiopathic hyperprolactinaemia

Tend to cause higher prolactin levels than idiopathic hyperprolactinaemia

PRL levels above 1000 mu/l are often due to adenoma; under 1009 iu/l, other causes such as compression, hypophysitis, null cell adenoma, etc. should be considered. Larger tumours are usually accompanied by higher blood levels.

Prolactinoma: most are less than 10 mm (microprolactinoma), rarely more than 10 mm (macroprolactinoma).

The compression of the optic chiasm results typically in a bitemporal hemianopia. MRI is more sensitive to small microadenomas than CT.

Generally the normal pituitary enlarges during pregnancy and a small but clinically non-significant enlargement is seen in microprolactinomas.

Rarely, tumours enlarge during pregnancy to produce headaches and visual defects.

Surgery is rarely now required even for large pituitary tumours, as these can be effectively treated with dopamine agonist therapy with rapid shrinkage, even with tumours that are compressing the optic chiasm.

14

Which of the following is true regarding oxytocin?
(Please select 1 option)
Causes milk ejection
Is a large polypeptide
Is released directly into the circulation from its site of production
Is synthesised in the posterior pituitary
Relaxes the uterus

Milk ejection

Oxytocin is synthesised in the hypothalamus and passes down the nerve axons to the posterior pituitary to be released into circulation.

The other hormone released by the posterior pituitary is antidiuretic hormone.

Oxytocin is involved in the control of smooth muscle contraction in the uterus and milk release from the lactating breast (the 'milk ejection reflex').

Oxytocin is a small peptide containing 9 amino acids.

15

Which of the following is correct in thyroid cancer?
(Please select 1 option)
Anaplastic carcinoma has a good prognosis if treated promptly
Follicular carcinoma spreads via the lymphatic system
Medullary carcinoma is associated with calcitonin
Papillary carcinoma is associated with MEN 1
The majority are follicular carcinomas

Medullary cancer associated with calcitonin

Anaplastic carcinomas of the thyroid are associated with poor prognosis.

Follicular carcinoma spreads via the blood stream.

MEN2 is associated with medullary carcinoma of the thyroid. Raised calcitonin levels are associated with medullary thyroid carcinoma.

Approximately 60% of patients presenting with a thyroid malignancy have a papillary carcinoma.

MEN1 is an inherited tumour syndrome, characterised by the development of tumours of the parathyroid, the anterior pituitary and the pancreatic islets.

16

Which of the following is caused by acute adrenal insufficiency?
(Please select 1 option)
Alkalosis
Hyperglycaemia
Hypernatraemia
Hypokalaemia
Hypotension

Hypotension

Patients with acute adrenocortical insufficiency (Addisonian crisis) may present with:

weakness
nausea and vomiting
abdominal pain
hypotension, and
fever.
Biochemical findings associated with adrenocortical insufficiency include:

Hyponatraemia
Hyperkalaemia
Acidosis, and
Hypoglycaemia.

17

Which of the following is true regarding aldosterone?
(Please select 1 option)
Acts on specific cell surface receptors
Is produced in the zona reticularis of the adrenal cortex
Secretion decreases when sodium intake is reduced
Secretion is increased following haematemesis
Secretion is increased in phaeochromocytoma

haematemesis

Aldosterone is produced in the zona glomerulosa of the adrenal cortex and acts via intracellular steroid receptors to increase sodium reabsorption.

It is regulated by the renin/angiotensin system. Its release is therefore stimulated by hypovolaemia and blood loss, and is inhibited by increased sodium intake/hypertension.

18

In the carcinoid syndrome, when the primary tumour is in the terminal ileum, which of the following is correct?
(Please select 1 option)
Dementia is a recognised consequence
Fibrosis affecting the aortic valve implies the presence of a right to left inter-atrial shunt
Pellagra is a recognised manifestation
Removing the primary tumour prolongs life expectancy
There is a decreased incidence of peptic ulceration

Although dementia is associated with pellagra there are no reports of dementia with carcinoid syndrome and it seems that only the dermatitis features.

Lesions of the mitral valve usually cause a right-sided or pulmonary shunt.

Pellagra is a recognised manifestation. This is due to nicotinamide deficiency.

It is not the case that removing the primary tumour prolongs life expectancy. This is because it is the metastases that cause the problems.

Peptic ulceration is a recognised association with carcinoid syndrome.

19

Which of the following conditions is not associated with pancreatic enzyme deficiency?
(Please select 1 option)
Benign pancreatic cystadenoma
Chronic pancreatitis
Crohn's disease
Cystic fibrosis
Pancreatic carcinoma

Crohns
Causes of pancreatic enzyme deficiency include conditions causing pancreatic destruction such as

Pancreatitis
Cystic fibrosis
Pancreatic infiltrative disorders
Any condition capable of causing pancreatic duct obstruction.
Zollinger-Ellison (ZE) tumours are usually neuroendocrine, often small and cause gastrin excess. Exocrine dysfunction is not associated.

20

With regard to calcium metabolism and its control, which of the following is correct?
(Please select 1 option)

Calcitonin causes decreased renal excretion of calcium

Cholecalciferol is 25-hydroxylated in the liver

In plasma, calcium binding to protein is pH independent

The average daily absorption of calcium from the diet is 100 mmol

The major stimulant to parathyroid hormone secretion is a fall in the plasma unionised calcium concentration

Cholecalciferol is 25-hydroxylated in the liver

A fall in ionised calcium causes the chief cells of the parathyroid to secrete PTH.

Fifty percent of extracellular calcium occurs as non-ionised protein bound calcium.

The degree of ionisation increases inversely with pH.

Calcitonin causes increased renal excretion.

21

Glucocorticoid therapy is unlikely to cause which of the following?
(Please select 1 option)
Amenorrhoea
Aseptic necrosis of the femoral head
Hyperkalaemia
Hypertrichosis
Lymphopenia

Glucocorticoids and steroids may cause iatrogenic Cushing's, with

Thin skin
Ease of bruising
Glucose intolerance/diabetes
Hypertension
Hypokalaemia
Hirsutism
Osteoporosis
and it may result in

Hypogonadotrophic hypogonadism (hence amenorrhoea).
Therapy may also be associated with aseptic necrosis of the femoral head.

22

Multiple endocrine neoplasia (MEN) type 2 consists of which of the following?
(Please select 1 option)
Adrenal cortex tumour
Papillary carcinoma of the thyroid
Parathyroid carcinoma
Phaeochromocytoma
Pituitary tumour

MEN type 2 is phaeochromocytoma, medullary cell carcinoma and hyperparathyroidism, often due to hyperplasia.

The RET proto-oncogene is usually a feature. Cortical adrenal adenomas are also recognised.

Pituitary tumours are a feature of MEN type 1.

23

Which of the following is correct regarding the basal metabolic rate (BMR)?
(Please select 1 option)
Decreases following major abdominal surgery
Increases with increasing age
Is greater in females than males
Is not related to lean body mass
Is the single largest component of energy expenditure

Is the single largest component of energy expenditure

BMR is higher in males than females, increases with increased muscle - that is, lean tissue - and declines with age.

Stress and illness cause an increase in BMR and a catabolic state.

24

Which of the following is untrue of 1,25-dihydroxycholecalciferol?
(Please select 1 option)
Binds to specific bone receptors
Decreases PTH release indirectly via effects on extracellular calcium concentrations
Exerts its effects via cell surface receptors
Increases intestinal absorption of phosphate
Reduces PTH release by direct effects on the parathyroid glands

Exerts its effects via cell surface receptors

1,25-dihydroxycholecalciferol is a steroid hormone with intra-cellular receptors.

Its effects on the parathyroids are direct and indirect.

25

With which of the following is hyperchloraemic metabolic acidosis associated?
(Please select 1 option)
An elevated anion gap
Hypothyroidism
Pancreatic fistula
Salicylate poisoning
Secondary hyperaldosteronism

Pancreatic fistula
Secondary hyperaldosteronism often found in association with cirrhosis is associated with a raised anion gap.

Hyperchloraemic acidosis would be associated with a normal/reduced anion gap.

Hyperparathyroidism is associated with this disorder.

A pancreatic fistula is associated with bicarbonate losses.

26

Which of the following statements is correct regarding papillary carcinoma of the thyroid gland?
(Please select 1 option)
After destruction of the normal thyroid tissue by tumour there is still uptake of iodine
Has a better prognosis than follicular carcinoma
Has a good response to chemotherapy
Is associated with hypocalcaemia in 20% of cases
Is the second most common cause of thyroid malignancy

Has a better prognosis than follicular carcinoma

Most tumours are 'cold' on radioisotope scan (123I or 99mTc). Some 20% will have normal or increased uptake. About 50% of tumours retain some ability to concentrate iodine. This explains the response of metastases to 131I. Radioactive iodine can be used to ablate any remaining thyroid tissue after total thyroidectomy for well-differentiated tumours larger than 1 cm diameter.

Prognosis - 10-year survival:

Papillary carcinoma 80%
Follicular 60%
Medullary (C cell) 50%
Anaplastic 0%.
Chemotherapy (doxorubicin) is of little benefit. The mainstay of treatment is 131I treatment. External beam radiotherapy may help in the treatment of bone metastases.

Medullary carcinomas (from the parafollicular C cells of the thyroid) secrete calcitonin. About 20% of these are associated with multiple endocrine adenomatosis (MEA) II a or b.

Papillary carcinoma is the commonest thyroid malignancy (60%). The others are:

Follicular (25%)
Anaplastic (10%)
Medullary (C cell) (5%)
Lymphoma about 1%.

27

Which of the following is correct regarding the syndrome of inappropriate antidiuretic hormone secretion (SIADH)?
(Please select 1 option)
A cause of dependent oedema
A complication of carbamazepine treatment
Typically associated with squamous cell bronchial carcinoma
Treated with furosemide
Typically associated with a serum osmolality of 295-315 mosm/kg (normal range 278-305)

Carbamazepine treatment

SIADH is associated with

Drugs, such as carbamazepine
Selective serotonin reuptake inhibitors (SSRIs)
Head injury
Tumours
Pneumonia
and typically,

Oat cell, rather than squamous cell lung cancer.
It may respond to demeclocycline (not furosemide).

It produces a euvolaemic hyponatraemia and dependent oedema is not a feature (if present it makes the diagnosis less likely).

Plasma osmolality is low and urine sodium and osmolality are high.

28

Of which of the following is hyponatraemia not a recognised complication?

Carbenoxolone therapy
Cerebral contusion
Congestive heart failure
Hepatocellular failure
Major surgery

Carbenoxolone therapy


Hyponatraemia can be classified as a hypovolaemic, euvolaemic or hypervolaemic state.

Hypovolaemic state is due to marked dehydration with excessive salt losses, for example, vomiting or Addison's disease.

Euvolaemic state typically reflects syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

Hypervolaemic state is due to conditions such as congestive cardiac failure (CCF), cirrhosis, nephrotic syndrome and myxoedema.

Carbenoxolone causes pseudohyperaldosteronism with hypertension, hypernatraemia and hypokalaemia.

Major surgery, pneumonia, subarachnoid, meningitis and injury (as well as drugs) can induce SIADH.

29

A 60-year-old woman presents to the surgical outpatient clinic with ulceration over the tips of the toes in her left foot and a large ulcer over her right heel. She also complains of paraesthesia in both feet.
The ankle-brachial pressure indices are 1.05 on the right and 1.2 on the left. On neurological assessment, proprioception and vibration sense are reduced.
Choose the single most appropriate diagnosis.
(Please select 1 option)
Hypertensive ulcer (Martorell's ulcer)
Neuropathic ulcer CorrectCorrect
Pyoderma gangrenosum
Squamous cell carcinoma
Vasculitic ulcer

This patient is most likely to have a neuropathic ulcer, usually resulting from peripheral sensory neuropathy secondary to diabetes mellitus.

The other causes for altered sensory neuropathy leading to neuropathic ulcers include

Spinal cord injuries
Spina bifida
Syringomyelia
Alcohol abuse and
Leprosy.
The usual sites in the lower limb for neuropathic ulceration are the head of the metatarsals, interdigital clefts, heel (calcaneum) and the lateral malleolus.

In diabetic patients, the ankle-brachial pressure indices may be falsely elevated, even in those with major vessel disease. This is due to calcification of the vessel walls and medial sclerosis.

Neurological assessment may reveal altered sensation, including proprioception and two point discrimination in the foot or toes, and reduced vibration sense.

30

Which of the following is not a classical feature of an addisonian crisis?
(Please select 1 option)
A high serum glucose This is the correct answerThis is the correct answer
A low plasma sodium IncorrectIncorrect answer selected
A raised blood urea
Fever
Occurrence during pregnancy

An addisonian crisis may be precipitated by any stressful event. Frequently this is an infection.

Pregnancy is a recognised cause. This may be due to increasing metabolic demands or vomiting.

The features of an addisonian crisis include

Hypotension
Hyponatraemia
Hyperkalaemia
Hyperuricaemia
Hypoglycaemia.

31

With what is a raised serum bicarbonate level consistent?
(Please select 1 option)
Chronic renal failure
Diabetic ketoacidosis
Glucose 6 phosphate deficiency
Hyperkalaemia
Pyloric stenosis

Pyloric stenosis

Chronic renal failure is associated with a mild acidosis.

In diabetic ketoacidosis the bicarbonate is low.

Glucose 6 phosphate deficiency is associated with a lactic acidosis.

A metabolic alkalosis usually accompanies hypokalaemia due to a shift of hydrogen ions from the extracellular to the intracellular space.

The loss of acid from persistent vomiting causes volume depletion and hypochloraemia.

32

Which of the following is true in the male reproductive system?
(Please select 1 option)
Luteinising hormone is not important in spermatogenesis
Oligospermia is improved by testosterone therapy
Prostatic secretions are essential for seminal liquefaction
Spermatogenesis is completed in about 30 days
The presence of testosterone is essential for follicle stimulatinghormone (FSH) to initiate spermatogenesis

Prostatic secretions are essential for seminal liquefaction

Luteinising hormone stimulates Leydig cell - steroidogenesis. Testosterone is normal for spermatogenesis.

Oligospermia may respond to gonadotrophin.

Spermatogenesis takes 70 to 80 days.

Sperm production is under FSH control.

33

Which of the following is true in diseases of the thyroid?
(Please select 1 option)
Anaesthetic agents and opiates can precipitate myxoedema coma
Hashimoto's disease is a cause of primary hypoparathyroidism
Pericardial effusions are a feature of hyperthyroidism
Radioactive iodine is associated with angina pectoris
Thyroid stimulating hormone (TSH) levels are reduced in primary hypothyroidism

Anaesthetic agents and opiates can precipitate myxoedema coma

Hypothyroidism can be primary or secondary to hypothalamic or pituitary disorders.

The causes of primary hypothyroidism can be classified as follows:

impaired synthesis or release of thyroid hormones
resistance to thyroid hormones
destruction of the endocrine gland (surgery, radioactive iodine)
autoimmune disease.
Hashimoto's disease is an autoimmune disorder that causes primary hypothyroidism (not hypoparathyroidism).

The TSH level is elevated in all cases of primary hypothyroidism (not reduced) and can be normal or low in secondary hypothyroidism.

The clinical features of hypothyroidism usually have an insidious onset, with females being more commonly affected than males.

The cardiovascular features include

pericardial effusions
bradycardia
electrocardiograph abnormalities (inversion or flattening of the T waves and low voltage complexes).
Myxoedema coma may be precipitated by anaesthetic agents, opiates, cold and infection, and may be the presenting feature of hypothyroidism.

Profound bradycardia, bradypnoea and hypothermia are common, which require urgent treatment with thyroxine. Thyroxine can cause angina pectoris in patients with ischaemic heart disease or heart failure.

34

Which of the following is true in thyroid storm?
(Please select 1 option)
Can be precipitated by surgery
May be precipitated by infection in a hypothyroid patient
Steroids should be withheld
The patient should be warmed with a Bair Hugger
Treatment should be delayed until the thyroid function test results are known

Surgery

A thyroid storm or crisis is a rare manifestation of hyperthyroidism, and may be precipitated by

Stress
Surgery
Infection.
Features include

Arrhythmias
Cardiac failure
Fever
Hyperventilation
Coma.
Treatment should be started immediately (not delayed until test results are known).

The management involves cooling and hydrating the patient, and the use of beta-blockers to control the arrhythmias. Corticosteroids, anti-thyroid drugs (for example, potassium iodide, carbimazole and propylthiouracil) and plasmapheresis may also be required.

35

Which one of the following is not a feature of diabetic ketoacidosis?
(Please select 1 option)
Glucose and ketones cause an osmotic diuresis
It occurs more often in type 1 diabetes patients
Kussmaul respiration is a feature
The acidosis is due to renal dysfunction
The breath may smell of acetone

The acidosis is due to renal dysfunction

In diabetic ketoacidosis (DKA) the lack of insulin leads to a breakdown of fat and the production of ketone bodies. The ketone bodies produce an acidosis which leads to deep, rapid breathing (Kussmaul respiration) in am attempt to blow off CO2.

Both the ketones and glucose produce an osmotic diuresis causing severe dehydration. The ketones smell of acetone, a pungent fruity smell.

Diabetic ketoacidosis is more common in type 1 diabetes.

36

Which of the following is true regarding the properties of drugs used for treating phaeochromocytoma?
(Please select 1 option)
Labetalol has stronger alpha-blocking than beta-blocking properties
Phenoxybenzamine is a pure alpha-1 blocker
Phentolamine blocks both alpha-1 and alpha-2 receptors
Prazosin blocks both alpha-1 and alpha-2 receptors
Tachyphylaxis may occur to beta-adrenergic blockers

Phentolamine

Labetalol is a stronger beta-blocker than an alpha-blocker (three to seven times greater).

Phenoxybenzamine and phentolamine block alpha-1 and alpha-2 receptors.

Prazosin is a selective alpha-1 blocker.

Tachyphylaxis can occur to alpha adrenergic blockers.

37

Hypertension is not associated with which one of the following conditions and features?
(Please select 1 option)
Acute intermittent porphyria and motor neuropathy
Adult polycystic kidney disease and an autosomal dominant mode of inheritance
Congenital adrenal hyperplasia
Conn's syndrome, with hypokalaemia and metabolic alkalosis
Cushing's syndrome, with sodium retention and potassium depletion

Acute intermittent porphyria and motor neuropathy

Primary (or essential) hypertension accounts for over 90% of cases of hypertension.

Secondary causes can be broadly classified as follows:

Renal: chronic glomerulonephritis/pyelonephritis, polycystic kidney disease, tumour, renal artery stenosis, obstruction, analgesic nephropathy
Endocrine: Cushing's syndrome, Conn's syndrome, congenital adrenal hyperplasia, phaeochromocytoma, acromegaly
Drugs: oral contraceptive pill, corticosteroids, monoamine oxidase inhibitors
Pregnancy: pre-eclampsia/eclampsia
Other: aortic coarctation, acute intermittent porphyria.
In Cushing's syndrome the elevated glucocorticoid levels, which have weak intrinsic mineralocorticoid properties, result in potassium depletion and sodium retention.

Conn's syndrome (primary hyperaldosteronism) causes hypernatraemia, hypokalaemia and a metabolic alkalosis.

38

Organ-specific autoimmune disease
A Antibodies to thyroid peroxidase and/or thyroglobulin
B Impaired absorption of vitamin B12
C Often follows an acute infection
D Often presents as a medical emergency
E Specific antibody binds and activates a receptor
Which organ-specific autoimmune disease is best described by each option?
Autoimmune hepatitis

Graves' disease

Hashimoto's thyroiditis

Pernicious anaemia

Type 1 diabetes mellitus

Autoimmune hepatitis results from aberrant presentation of HLA class II by hepatocytes, often following acute liver infection.

In Graves' disease, an autoantibody to the thyroid stimulating hormone (TSH) receptor causes activation and increased thyroid activity. This results in hyperthyroidism.

Hashimoto's thyroiditis is a condition in which autoantibodies destroy thyroid peroxidase or thyroglobulin. Although this may initially cause hyperthyroidism, it is typically characterised by hypothyroidism.

Pernicious anaemia is caused by deficient absorption of vitamin B12. Absorption of this vitamin requires intrinsic factor which is the target of the autoimmune process in this condition along with atrophic gastritis and loss of gastric parietal cells.

Type 1 diabetes follows an autoimmune response against β-cells in the pancreatic islets of Langerhans. It typically presents acutely, as symptoms only result once a critical volume of pancreatic cells (~90%) are destroyed.

39

Which of the following is not an anatomical relation of the pituitary gland?
(Please select 1 option)
Diaphragma sellae
Foramen magnum
Optic chiasm
Sphenoidal air sinuses
Temporal lobe

Foramen Magnum

The diaphragma sellae roofs the pituitary fossa, with the optic chiasm located superiorly, the sphenoidal air sinus inferiorly, and the temporal lobes laterally located.

Both cavernous sinuses lie laterally.

40

Which of the following is true regarding a thyroglossal cyst?

Contains lymphoid tissue
Is a pre-malignant condition
Is commonly located in a suprahyoid position
Is formed after the failed disintegration of the hypoglossal tract
Usually presents in patients of middle age

Contains lymphoid tissue

The majority of thyroglossal cysts (60%) typically present as midline swelling that moves with swallowing or on protruding the tongue. They are formed after the failed disintegration of the thyroglossal tract and are most commonly located in a subhyoid position.

The cysts may become infected and cause chronic discharge. Infected cysts are treated by needle aspiration and antimicrobials.

The presence of lymphoid tissue in the wall renders the cysts susceptible to infection.

41

Thyroid nodules are associated with which of the following?

Atenolol therapy
Multiple endocrine neoplasia type 1
Pendred's syndrome
Phaeochromocytoma
von Hippel-Lindau disease

Pendred syndrome

Thyroid nodules may be associated with

Any autoimmune thyroid disease (Hashimoto's and Graves')
Thyroid malignancy (not MEN type 1 - parathyroid, pituitary and pancreatic)
Pendred's syndrome (sensorineural deafness and goitre).
von Hippel-Lindau disease is associated with

Phaeochromocytoma
Haemangioma
Hypernephroma.

42

Which of the following are associated with enlargement of the thyroid?

Lithium
Nitrofurantoin
Omeprazole
Penicillin antibiotics
Propylthiouracil (PTU)

Drug causes of goitre include

Lithium
Amiodarone
Iodine containing compounds
Some sulphonylureas
Sulphonamides.
Carbimazole and PTU block the iodination of the thyroid hormones, and some reduce the size of goitre.

43

Which of the following is true regarding phaeochromocytoma?

20% are extra-adrenal in origin
90% are malignant
Is diagnosed using octreotide scintigraphy
Is found below the diaphragm in over 90% of occasions
Is typically associated with von Hippel-Lindau

The rule of tens applies to phaeochromocytoma:

10% are extra-adrenal
10% are malignant
10% are familial (such as vHL, MEN type 2 and neurofibromatosis).
They are found below the diaphragm in over 90% of occasions.

They are diagnosed typically with measurement of urinary normetadrenalines and occasionally MIBG scintigraphy may be useful.

44

Which of the following is true regarding aldosterone?
(Please select 1 option)
Has a constant level of secretion
Has an equal affinity to cortisol for the mineralocorticoid receptor
Is secreted by the zona fasciculata
Is synthesised from amino acids
Secretion increases in the presence of hypokalaemia

Has an equal affinity to cortisol for the mineralocorticoid receptor

Aldosterone is a steroid hormone (mineralocorticoid) synthesised from cholesterol by the enzyme aldosterone synthetase. It is formed in zona glomerulosa, which is the outer section of the adrenal cortex. It helps regulate the electrolyte balance by stimulating the excretion of potassium ions and retaining sodium ions and water. The mineralocorticoid receptors (MR) are intracellular.

Aldosterone is synthesised in reaction to increases of angiotensin II, or plasma potassium, which are present in proportion to sodium deficiencies. Sodium deficiency and adrenocorticotrophic hormone (short term stimulation only) also stimulate aldosterone secretion. Atrial natriuretic hormone or peptide, hypernatraemia and hypokalaemia suppress aldosterone secretion. Aldosterone secretion has a diurnal rhythm, with approximately 75% being secreted between 0400 and 1000 hours.

The mineralocorticoid receptor binds both aldosterone and cortisol with equal affinity. Moreover, the same DNA sequence serves as a hormone response element for the activated (steroid-bound) forms of both mineralocorticoid and glucocorticoid receptors.

How then can aldosterone stimulate specific biological effects in this kind of system, particularly when blood concentrations of cortisol are something like 2000-fold higher than aldosterone?

A large part of the answer is that in aldosterone-responsive cells, cortisol is effectively destroyed, allowing aldosterone to bind its receptor without competition. Target cells for aldosterone express the enzyme 11-beta-hydroxysteroid dehydrogenase, which has no effect on aldosterone, but converts cortisol to cortisone, which has only a very weak affinity for the mineralocorticoid receptor. In essence, this enzyme 'protects' the cell from cortisol, and allows aldosterone to act appropriately.

Some tissues (for example, hippocampus) express abundant mineralocorticoid receptors, but not 11-beta HSD; they therefore do not show responses to aldosterone, because aldosterone is not present in quantities sufficient to compete with cortisol.

An interesting demonstration of this enzyme protection system is seen in chronic liquorice intoxication for the activated (steroid-bound) forms of both mineralocorticoid and glucocorticoid receptors.

45

Which of the following conditions is not associated with multiple endocrine neoplasia type 2b?
(Please select 1 option)
Marfanoid body habitus IncorrectIncorrect answer selected
Medullary thyroid carcinoma
Neuromas
Parathyroid tumours This is the correct answerThis is the correct answer
Phaeochromocytoma

Multiple endocrine neoplasia (MEN) are inherited familial (autosomal dominant) neoplastic conditions affecting various endocrine glands.

There are three main types of MEN syndromes:

MEN 1 (Werner syndrome)
MEN 2a
MEN 2b.
Although MEN 1 and MEN 2 have some common clinical features they are genetically unrelated conditions.

MEN 1 is characterised by

Parathyroid tumours
Pancreatic tumours (including Zollinger-Ellison syndrome)
Pituitary tumours.
MEN 2a (also known as Sipple's syndrome) consists of

Medullary carcinoma of the thyroid
Phaeochromocytoma
Parathyroid tumours.
Patients with MEN 2a usually present in the fourth and fifth decade of life.

MEN 2b consists of

Medullary carcinoma of the thyroid
Phaeochromocytoma
Neuromata
Marfanoid habitus.
Intestinal ganglioneuromatosis occurs in about 75% of patients MEN 2b. Delayed puberty is another important feature of MEN 2b syndrome.

46

A 60-year-old male presents with diarrhoea and flushes. A diagnosis of carcinoid syndrome is suspected.
Which one of the following statements is true?
(Please select 1 option)
Deranged electrolytes are infrequently seen
It is associated with left-sided cardiac valve lesions
Small bowel carcinoid tumours rarely metastasise to the liver
Tumours arise from enterochromaffin cells CorrectCorrect
Urinary bradykinin concentrations may be elevated

Carcinoid tumours may secrete

5-Hydroxytryptamine (5-HT)
Bradykinin
Histamine
Substance P
Prostaglandins.
The tumours arise in enterochromaffin (argentaffin) cells and produce symptoms when peripheral levels of 5-HT, etc. reach high levels.

Thirty-six per cent of tumours are found in the small bowel and metastasise to the liver before causing the syndrome. They are also found in the

Lung
Pancreas
Large bowel
Stomach.
The classic syndrome is of diarrhoea, flushing with hypotension, telangiectasia and bronchospasm. Less commonly, hypertension and right-sided heart valve lesions are seen.

A raised urinary 5-hydroxyindoleacetic acid (5-HIAA) on a low serotonin diet is diagnostic.

Electrolyte imbalance and malnutrition are seen when diarrhoea is the primary clinical manifestation

47

A 58-year-old female is admitted for laparoscopic adrenalectomy for a right-sided phaeochromocytoma.
Which one of the following statements concerning her management is correct?
(Please select 1 option)
Glucagons should be used to treat post-operative hypoglycaemia
Hypotension is an anticipated immediate post-operative complication CorrectCorrect
Hypotension may persist post-operatively
IV hydrocortisone is usually required post-operatively

Phenoxybenzamine and propranolol should be commenced the day prior to surgery
Phaeochromocytoma is a tumour of the chromaffin cells, usually within the adrenal medulla. Ten per cent are bilateral and 10% are malignant tumours. It may occur as part of multiple endocrine adenomatosis or in association with neurofibromatosis.

Symptoms are related to the secretion of epinephrine (adrenaline) and norepinephrine (noradrenaline).

Treatment consists of pharmacological control of blood pressure and heart rate, using alpha- and beta-receptor antagonists usually commenced weeks before surgery. A standard combination is phenoxybenzamine (alpha) and propranolol (beta), but the alpha-blockade must be initiated before the beta-blockade to avoid exacerbating the hypertension.

These patients require invasive cardiovascular monitoring (arterial line and central venous catheter) which should be continued into the postoperative period. The blood pressure may fall markedly following removal of the tumour (low blood volume and persistent alpha-blockade) and a norepinephrine infusion may be required. Steroids are usually not required as sufficient corticosteroids are released by the remaining adrenal gland.

Patients are all electively admitted into the intensive care unit for at least 24 hours postoperatively, due to continuing cardiovascular instability. A chest x ray is required is confirm correct placement of the central venous catheter and to rule out a pneumothorax.

Hypoglycaemia may occur (treated with glucose/dextrose infusions), and hypertension can persist for up to four days, despite completely removing the tumour.

48

A 50-year-old male is admitted for elective varicose vein stripping.
He has a five year history of type 2 diabetes for which he takes metformin. His last HbA1c checked at annual review was 7% (3.8-6.4).
Which of the following statements regarding part of his pre-operative management is correct?
(Please select 1 option)
Can eat a light/early breakfast on the day of surgery
Is unsuitable for day case surgery
Requires a pre-operative intravenous infusion of Actrapid by sliding scale
Should be admitted the day before surgery
Should be first on an operating list

Diabetic patients, regardless of whether they are insulin dependent (type 1) or non-insulin dependent (type 2), should be scheduled for surgery early in the day. However, placing them first on the list is not always possible and this is widely accepted.

Diabetics as a rule are kept nil by mouth for the same duration (six hours for solids and two hours for clear fluids) as all patients scheduled for general anaesthesia.

The pre-operative management of diabetics is influenced by the method and efficiency of glucose control, rather than the type of diabetes they have. Patients with poor control of blood glucose should be admitted the day before and started on an insulin/glucose sliding scale until they reach the operating theatre. Thus optimal control of blood glucose can be achieved and monitored by frequent bedside assessment of the blood glucose (for example BM stix). However, this patient's glycaemic control appears good, as reflected by a HbA1c of 7%.

Well controlled diabetics can be treated as day cases, but they should omit the long acting oral hypoglycaemic drug or insulin the night before surgery. Blood glucose monitoring is still necessary, but they rarely require an insulin/glucose sliding scale.

49

Which of the following is true regarding neuroendocrine tumours?
(Please select 1 option)
Diarrhoea is an uncommon feature in the gastrinoma syndrome
Elevated calcitonin is a feature of the MEN type 1
High plasma chromogranin A concentrations are feature of carcinoid syndrome CorrectCorrect
Mitral stenosis is a feature of carcinoid syndrome
Thromboembolic events are uncommon in the glucagonoma syndrome
Calcitonin is elevated in association with medullary thyroid cancer found in MEN type 2.

Chromogranin A and B are elevated in association with carcinoid, as are urine 5-HIAA concentrations.

Right-sided cardiac valvular lesions are found in association with carcinoid due to the secretion of histamine/bradykinin/5-HT which is metabolised by the lung, thus preventing left-sided cardiac lesions.

Migratory thromboses and necrolytic migratory erythema are features of glucagonoma.

50

In an otherwise asymptomatic 60-year-old patient with primary hyperparathyroidism, which one of the following is an indication for parathyroidectomy?
(Please select 1 option)
A serum calcium concentration 2.9 mmol/l (2.2-2.6)
Hypertension
Osteoarthritis
Renal calculi
Urinary calcium excretion 6 mmol/24 hours (

Renal calculi

Clearly, indications for surgery would include symptomatology such as

Polyuria/polydipsia
Nephrolithiasis
Bone disease.
In asymptomatic disease the indications are less clear but would include

Calcium above 3 mmol/l
Hypercalciuria above 10 mmol/day
Osteoporosis on DEXA
Age less than 50.

51

A 22-year-old male presents to the surgical clinic with gynaecomastia.
Which one of the following would be responsible for his presentation?
(Please select 1 option)
Crohn's disease
Hodgkin's disease
Pancreatitis
Proton pump inhibitor treatment
Seminoma

Seminoma
Causes of gynaecomastia include

Congenital, such as Klinefelter's
Drugs, such as digoxin
Tumours, such as seminoma.
Anabolic steroid therapy is a well recognised cause in young males.

52

Which of the following is correct regarding primary hyperparathyroidism?
(Please select 1 option)
Is associated with bone resorption by PTH to restore depressed serum calcium levels to normal
Is associated with hypocalciuria due to elevated PTH levels
Is usually caused by an adenoma of a single parathyroid gland
Progresses to tertiary hyperparathyroidism with time

Is usually caused by an adenoma of a single parathyroid gland

Primary hyperparathyroidism is associated with hypercalcaemia and hypophosphataemia. There is also usually hypercalciuria.

It is usually a consequence of a single adenoma, but may be associated with hyperplasia and rarely carcinoma, where parathyroid hormone (PTH) concentrations may be particularly high.

53

Gynaecomastia is caused by which of the following?

Bronchial carcinoma
Hydrocoele
Oesophageal carcinoma
Transitional cell carcinoma of the bladder
Varicocoele

Causes of gynaecomastia include;

chromosomal abnormalities
hyperthyroidism
drugs, such as digoxin
bronchial carcinoma/teratoma/seminoma.

54

Raised serum inorganic phosphate is found in which of the following?
(Please select 1 option)
Acromegaly
Chronic obstructive jaundice
Dietary rickets
Hyperthyroidism
Renal tubular acidosis

Hyperphosphataemia is associated with acromegaly as growth hormone causes phosphate reabsorption.

Pseudo-hypoparathyroidism is also associated with hyperphosphataemia.

Renal tubular acidosis and dietary rickets are associated with hypophosphataemia.

55

Which one of the following commonly used drugs has been shown to cause a rise in blood glucose when used in normal pharmacological doses?
(Please select 1 option)
Aspirin
Atenolol
Dexamethasone
Morphine sulphate
Potassium-sparing diuretics

Drugs that may cause hyperglycaemia typically include

Corticosteroids
Thiazide diuretics
Glucagon.
Atenolol is associated with hypoglycaemia.

56

Which of the following is correct regarding gastrin?
(Please select 1 option)
Is predominantly produced by G cells located in the pancreas
Levels are decreased in atrophic gastritis (pernicious anaemia)
Stimulates gastric acid secretion in response to gastric emptying
Stimulates insulin secretion, particularly after a carbohydrate meal
Stimulates the growth of cells in the gastric mucosa

Gastrin has a variety of actions, but its principal physiological actions are

• Stimulation of gastric acid (in response to food entering the stomach)
• Pepsin secretion
• Stimulation of the growth of the mucosa of the stomach and intestine.

Gastrin is normally mainly produced in the G cells in the gastric antrum, and is also produced in the duodenum.

Gastrin is produced in the pancreas in the fetus, and in adults with pancreatic gastrin secreting tumours (gastrinomas).

Levels are increased in conditions of low acid production, for example, atrophic gastritis and proton pump inhibitor (PPI) therapy due to loss of negative feedback.

The only time gastrin levels are high enough to stimulate insulin secretion is following a protein meal.

57

Hypercalcaemia is not associated with which of the following?
(Please select 1 option)
Acute renal failure
Excessive absorbable alkali consumption
Sarcoidosis
Secondary hyperparathyroidism
Thyrotoxicosis

Secondary hyperparathyroidism
Hypercalcaemia may occur in association with

Hyperparathyroidism
Vitamin D
Sarcoid
Addison's disease
Milk alkali syndrome
Thyrotoxicosis.
Secondary hyperparathyroidism is associated with hypocalcaemia with chronic renal failure and impairment of 1 alpha-hydroxylation of vitamin D by the kidneys.

58

Which of the following is a radiological feature of hyperparathyroidism?
(Please select 1 option)
Bone cysts
Decalcification of cartilage
Pancreatic calcification
Radio-lucent renal calculi
Short fourth metacarpal

Bone cysts

Decalcification of cartilage is a feature of pseudogout/calcium pyrophosphate arthropathy

Pancreatic calcification is a feature of chronic pancreatitis.

Radio-opaque calcific stones, as opposed to Radio-lucent renal calculi, are a feature of hyperparathyroidism.

A short fourth metacarpal is a feature of pseudohypoparathyroidism.

59

Which of the following is true regarding primary hyperaldosteronism (Conn's syndrome)?
(Please select 1 option)
Associated with hyperkalaemic hypertension
May be investigated with a metaiodobenzylguanidine (MIBG) scan
May be treated with spironolactone
Plasma renin concentration is elevated
Usually due to bilateral adrenal hyperplasia

Conn's syndrome is associated with hypokalaemic hypertension.

MIBG is used in phaeochromocytoma.

Primary hyperaldosteronism may respond successfully to spironolactone, and spironolactone therapy may be a useful indication of the response of blood pressure following surgery. The iodocholesterol scan may be useful for localisation.

Plasma renin concentration is low.

Primary hyperaldosteronism is usually (70%) due to unilateral adenoma.

60

Which of the following is true of diabetic ketoacidosis (DKA)?

Does not occur in type 2 diabetics
Is usually associated with hypokalaemia
Is due to unregulated glycogen breakdown from the liver
May be precipitated by metformin
May be the first presentation of diabetes in up to 25% of cases.

May be the first presentation of diabetes in up to 25% of cases.

DKA is due to unregulated lipolysis with the release of free fatty acids hence causing the acidosis and is due to insulin insufficiency. It is well recognised to occur in Type 2 diabetics.

It is associated with:

Hyperglycaemia: glucose >11.1mmol/L
Acidosis: A low pH (11.1 mmol/L
Low bicarbonate (

61

Obesity is not associated with a higher risk of developing which of the following?
(Please select 1 option)
Breast carcinoma
Diabetes mellitus
Osteoarthritis
Osteoporosis
Renal carcinoma

Osteoporosis

Obesity is associated with a higher risk of:

Osteoarthritis
Carcinoma of the breast, kidney and prostate,
Hypertension
Diabetes mellitus, and
Psychiatric conditions such as depression.
It is relatively protective for osteoporosis.

62

In which is the growth of the following malignancies dependent on the growth factor/hormone indicated?
(Please select 1 option)
Breast cancer and testosterone
Endometrial cancer and oestrogens
Myeloma and interleukin-12
Prostate cancer and oestrogens
Thyroid cancer and thyroxine

Endometrial cancer

While autonomy of growth is a feature of neoplasia, some neoplasms depend on certain growth factors/hormones for growth.

A large proportion of breast cancers express oestrogen receptors and the expression of these receptors correlates with response to oestrogen blockade.

Prostate epithelium is dependent on androgens for growth and survival, castration results in apoptosis and partial involution of the gland. This characteristic is retained by most prostate carcinomas and thus their growth can be inhibited by androgen blockade.

Thyroid cancer responds to the stimulatory effects of thyroid-stimulating hormone (TSH) and this can be inhibited post thyroidectomy with thyroxine.

Interleukin-6 (not interleucin 12) is a potent growth factor for myeloma.

Endometrial cancer is markedly increased in patients receiving unopposed oestrogen therapy and advanced disease may be treated with progesterone therapy which shrinks the tumour.

63

A 48-year-old male insulin dependent diabetic with no other significant past medical history is being prepared for a right hemicolectomy for a caecal carcinoma.
In these circumstances which of the following is correct?
(Please select 1 option)
He is unlikely to have any undiagnosed ischaemic heart disease.
He should be last on the operating list as this is likely to be a contaminated case.
He should be on a sliding scale the night before surgery.
His insulin requirements may decrease in the post-operative period.
With tight glycaemic control, his risk of wound infection is the same as a non-diabetic patient.

Insulin dependent diabetics should be admitted the day before surgery and commenced on sliding scale insulin.

They should be placed first on the operating list where possible to minimise risks of hypoglycaemia.

Diabetics have a risk of suffering previously undiagnosed ischaemic heart disease, renal impairment and autonomic neuropathy and pre-operative ECG, U+Es and lying / standing BP should be checked.

Tight glycaemic control reduces risks of post-operative wound infection in diabetics but they carry a higher risk of post-operative wound infection and poor wound healing than non-diabetic patients.

In the post-operative period insulin requirements are likely to increase because of the stress response to surgery.

64

Which of the following does the human testis not secrete?
(Please select 1 option)
Androstenedione
Inhibin
Luteinising hormone (LH)
Oestradiol
Testosterone

LH

The testis is responsible for secreting testosterone, androstenedione, oestradiol, inhibin as well as a small amount of progesterone.

The anterior pituitary produces LH and follicle-stimulating hormone (FSH).

Fructose and prostaglandins that nourish the spermatozoa are secreted by the seminal vesicles.

65

Which of the following is true of glycosylated haemoglobin?
(Please select 1 option)
Is absent in the plasma of people without diabetes mellitus
Is increased in diabetic patient with concurrent sickle cell disease
Results from the combination of a haemoglobin A and sugar moiety
The levels of Hb A1c are a poor index of glucose-induced renal dysfunction in diabetics
When measured as HbA1c in plasma gives a more accurate retrospective estimates of blood sugar levels than other glycosylated products

Glycosylated haemoglobin is found in the normal population but the percentage is lower than in patients with diabetes.

The risk of renal damage such as microalbuminuria increases when HbA 1c exceeds 8%.

Glycosylated haemoglobin is formed through the non-enzymatic binding of a hexose to the N-terminal amino acid of the beta-chain.

Glycosylated serum proteins such as fructosamine are more accurate than glycosylated haemoglobin for the retrospective estimation of blood sugar levels.

Patients with sickle cell disease and haemolytic diseases have decreased survival span of red blood cells and therefore glycosylation is reduced.

66

Which one of the following confirms a diagnosis of diabetes mellitus? (Normal range fasting glucose 3.0-6.0 mmol/L)
(Please select 1 option)
Fasting plasma glucose of 6.5 mmol/L
Fasting plasma glucose of 6.9 mmol/L
Fasting plasma glucose of 7.1 mmol/L
Random plasma glucose of 9.8 mmol/L
Random plasma glucose of 10.5 mmol/L

Diabetes mellitus may be confirmed with a fasting plasma glucose above 7 mmol/L and a random plasma glucose above 11.1 mmol/L.

These criteria are particularly important as the diagnosis of diabetes confers extra risk both anaesthetically and postoperatively.

67

Which one of the following would be expected to provide a definitive treatment for Graves' thyrotoxicosis?
(Please select 1 option)
Carbimazole
Hemithyroidectomy
Lithium
Radio-iodine treatment
Steroids

Radioiodine

Only total thyroidectomy and radioiodine can provide a definitive treatment for thyrotoxicosis.

Others are used in the treatment of Graves' disease but will not produce a definitive/permanent treatment.

68

Which of the following is true regarding the thyroid gland?
(Please select 1 option)
Develops from the endoderm between the second and third pharyngeal pouches
Has C cells that are derived from the ultimobranchial body
Is at the level of the third to fifth cervical vertebrae
May have accessory nodules in the hyoid
Usually weighs about 100 g

Has C cells that are derived from the ultimobranchial body

The thyroid gland develops from the first and second pharyngeal pouches.

The C cells are responsible for the secretion of calcitonin.

Accessory nodules are well recognised in the base of the tongue.

It ususally weighs about 25 g.

69

Which of the following is correct regarding primary hyperparathyroidism?
(Please select 1 option)
Is almost always associated with generalised muscle weakness
Is a cause of recurrent renal calculi
Is associated with corneal calcium reabsorption
Is a cause of periosteal new bone formation
Is associated with osteo-arthropathy

Recurrent renal stones

Hyperparathyroidism is associated with the biochemical abnormalities of

Hypercalcaemia
Hypophosphataemia
Hypercalciuria
Elevated PTH concentrations.
Most patients are asymptomatic but symptoms include

'Bones' - arthralgia
'Moans'- depression
'Stones' - renal calculi
'Groans' - peptic ulceration.
Polyuria and polydipsia may be presenting features; weakness particularly with markedly elevated calcium may be a feature in about 5%.

Pseudogout (calcium pyrophosphate arthropathy) is more common in association with hyperPTH.

Primary hyperparathyroidism is a cause of subperiosteal bone resorption not a cause of periosteal new bone formation. It is associated with pyrophosphate arthropathy not osteo-arthropathy.

70

Which of the following is true of an insulinoma?
(Please select 1 option)
Is associated with peptic ulceration
Is associated with Whipple's disease
Is usually associated with a raised insulin:proinsulin ratio
May be malignant
Leads to hyperglycaemia after prolonged fast (48 hours) in most cases

May be malignant

Insulinoma, a rare beta cell tumour, presents with classical Whipple's triad (not disease) consisting of

Attacks precipitated by exercise/fasting
Attacks associated with confirmed hypoglycaemia and
Relieved by glucose.
It is malignant in approximately 10% of cases and is associated with MEN type 1.

It is the gastrinoma that is associated with peptic ulceration rather than insulinoma.

Typically, the insulin:proinsulin ratio is similar as a raised ratio suggests exogenous insulin as a cause of the hypoglycaemia.

71

Which of the following is true of antidiuretic hormone (ADH)?
(Please select 1 option)
Acts on the proximal convoluted tubule
Is synthesised in the posterior pituitary IncorrectIncorrect answer selected
Is inappropriately released in association with gastric carcinoma
Release is normally inhibited following surgery
Release is inhibited when the central venous pressure is high

Release is inhibited when the central venous pressure is high

ADH is a nonapeptide, synthesised in the hypothalamus and conveyed to the posterior pituitary via the pituitary stalk.

It acts on the distal convoluted tubule and collecting ducts to increase permeability to water and is responsible for water retention but not salt.

It is released in volume depletion and frequently following surgery.

It is inhibited by volume excess.

Inappropriate secretion (SIADH) is most commonly associated with lung carcinoma but also mesothelioma, duodenal, pancreatic and colon tumours and many others.

72

hich of the following is true of glucagon?
(Please select 1 option)
Has negative inotropic effects on the heart
Inhibition of insulin secretion
Inhibits hepatic gluconeogenesis
Is secreted from the beta-islet cells of the pancreas
Stimulates hepatic glycogenolysis

Glucagon causes the recruitment of glucose from hepatic stores and has a positive inotropic effect on the heart. Paradoxically, it stimulates insulin release.

Secretion is from the alpha-islet cells of the pancreas after injury.

73

Which of the following is not included in the treatment of thyrotoxic crisis?
(Please select 1 option)
Administration of beta blocking agents
Administration of iodide
High dose dexamethasone
Immediate administration of propylthiouracil
Keeping the patient warm

The mainstay of treatment are steroids, with Lugol's iodine (given with carbimazole/PTU although this takes days to begin working) and beta-blockers.

Generally hyperthermia is a feature and patients require cooling.

74

In which of the following do ulcers on the plantar surface of the foot occur?
(Please select 1 option)
Diabetes mellitus
Lead neuropathy
Sickle-cell disease
Varicose veins
Vasculitis

Plantar ulcers typically occur in association with sensory neuropathy (as in diabetes and alcohol).

Lead causes a motor neuropathy

75

Which of the following is correct concerning 1,25(OH)2 vitamin D?
(Please select 1 option)
25 hydroxylation occurs in the kidney
Increased in chronic renal failure IncorrectIncorrect answer selected
Inhibits phosphate and calcium absorption from the gut
Stimulated by hyperphosphataemia
Stimulates bone reabsorption This is the correct answerThis is the correct answer

25 hydroxylation occurs in the liver. 1 hydroxylation is in the kidney.

Hypophosphataemia and hypocalcaemia are the main stimulants of 1 alpha hydroxylation.

The major action of 1,25(OH)2is to stimulate calcium absorption from the gut but can also inhibit osteoblastic action.

Renal failure reduces 1 hydroxylation resulting in decreased 1,25 (OH)2.

76

Diarrhoea is not a presenting feature in which of the following?
(Please select 1 option)
Carcinoid syndrome
Cushing's syndrome
Hypoparathyroidism
Primary hyperaldosteronism
Thyrotoxicosis

Carcinoid syndrome and thyrotoxicosis are two easy points.

Hypoparathyroidism is rarely reported to present with diarrhoea.

Primary hyperaldosteronism does not have any tangible association with diarrhoea but Cushing's syndrome can cause diarrhoea.

77

Which of the following is correct regarding carcinoid?
(Please select 1 option)
Induced diarrhoea is increased by octreotide
Is associated with bronchodilatation
Is associated with fibrosis of the heart valves
Most commonly involves the terminal ileum
Most patients die within two months of the diagnosis

Fibrosis of heart valves

Octreotide is effective for symptom control and in many cases causes tumour shrinkage but its effect usually wears off.

Appendix is the most common site.

Most tumours are slow growing. Five year survival is as follows:

Locally invasive only 95%
Regional lymph nodes positive 65%
Metastases present 20%.