Clinical SBAs
Clinical Endocrinology: (27 questions)

Questions

• 1
  Which of the following is the correct pair of medication and side-effect?
  Difficulty: Hard     Topic: Hypoglycaemic agents side-effects
  a

  Metformin - hepatic cirrhosis

  b

  Gliclazide - paroxysmal cough

  c

  Acarbose - Steven's Johnson syndrome

  d

  Exenatide - hypoglycaemia

  e

  Vildagliptin - LFT changes
  Explanation: Vildagliptin is a DPP-4 inhibitor and causes GI effects and raised LFT. Metformin causes GI upset, rash and lactic acidosis (rare and life-threatening). Gliclazide cause hypoglycaemia, weight gain and skin reaction. Acarbose is an alpha-glucosidase inhibitor and it causes severe flatulence and diarrhoea. Exenatide causes GI upset, headache and dizziness.
• 2
  A 45-year old man presents with new onset diabetes, increased spacing between teeth and states that his shoes no longer fit. Which of the following his management is not correct?
  Difficulty: Hard     Topic: New diabetes with spaced teeth
  a

  Transphenoidal resection may be used

  b

  Octreotide is an effective antagonist

  c

  Radiotherapy gives rapid response

  d

  Visual field assessment is important

  e

  Oral glucose tolerance test is part of making the diagnosis
  Explanation: This man has acromegaly. Diagnosis uses OGTT, demonstrating failure of glucose to suppress GH release. Pituitary adenomas cause bitemporal hemianopia therefore fields are assessed. Best treatment is resection, via a transphenoidal approach. Octreotide (a somatostatin analogue) can be used to antagonise the effects of excess GH while awaiting surgery. Radiotherapy has got some effect but it takes up to 2 years to have an effect therefore is least important of the options given.
• 3
  A 30-year old man with schizophrenia presents with impotence and galactorrhoea. What is the most appropriate management?
  Difficulty: Medium     Topic: Impotence and galactorrhoea
  a

  Reassurance and follow-up

  b

  Stop risperidone

  c

  Start domperidone

  d

  Start bromocriptine

  e

  Transphenoidal resection
  Explanation: Impotence and galactorrhoea are signs of prolactin excess that can be due to a prolactinoma or secondary to dopamine antagonism. Normally dopamine inhibits the release of prolactin. Anti-psychotics are medications used chronically that can cause hyperprolactinaemia, risperidone is one example. Domperidone is a dopamine antagonist, which would worsen the symptoms. Bromocriptine is a dopamine agonist that is 1st line treatment for prolactinomas, cabergoline is an alternative medication. Transphenoidal resection is used for prolactinomas not responding medically.
• 4
  A 20-year old man is found to have hypogonadotrophic hypogonadism. He also suffers from anosmia and colour blindness. What is the most likely diagnosis?
  Difficulty: Hard     Topic: Hypogonadotrophic hypogonadism
  a

  Kallman's syndrome

  b

  Laurence-Moon-Biedl syndrome

  c

  Klinefelter's syndrome

  d

  Prader-Willi syndrome

  e

  Refsum's syndrome
  Explanation: This man has Kallman's syndrome, which causes secondary gonadal failure due to lack of LH and FSH from the pituitary. Its associated with reduced colour vision and inability to smell. Laurence-Moon-Biedl syndrome is another cause of secondary hypogonadism, with retinitis pigmentosa, polydactyly, obesity and reduced IQ. Klinefelter's (47XXY) causes primary gonadal failure. Prader-Willi is an inherited syndrome with learning disability, hyperphagia, hypogonadism and diabetes. Refsum's is an inherited cause of neurodegeneration with onset at 2yrs.
• 5
  A 60-year old lady with resistant hypertension is found to be hypokalaemic with a raised aldosterone/renin ratio. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Resistant hypertension with hypokalaemia
  a

  Acromegaly

  b

  Addison's disease

  c

  Conn's syndrome

  d

  Cushing's syndrome

  e

  Renal artery stenosis
  Explanation: Conn's syndrome is primary hyperaldosteronism, which is almost always due to an adenoma of the adrenal cortex. It often presents as resistant hypertension. High aldosterone promotes potassium excretion resulting in hypokalaemia and metabolic alkalosis. Raised aldosterone to renin ratio is highly suggestive. Treatment is with resection. Acromegaly, Cushing syndrome and renal artery stenosis can cause hypertension but do not alter the aldosterone-renin ratio. Addison's causes hypotension.
• 6
  Which of the following is not true of primary Addison’s disease?
  Difficulty: Easy     Topic: Addison's disease
  a

  It can occur due to meningococcal septicaemia

  b

  The most common cause worldwide is TB

  c

  There is hypernatraemia and hypokalaemia

  d

  It is associated with vitiligo

  e

  ACTH is raised
  Explanation: Addison's is adrenocortical failure, mostly due to TB worldwide but due to autoimmune disease in the West. The autoimmune form is associated with vitiligo, thyroid disease, type 1 diabetes and pernicious anaemia. Waterhouse-Friderichsen syndrome is a rare cause due to bilateral adrenal haemorrhage in meningococcal septicaemia. Lack of mineralocoroticoid action causes hyponatraemia and hyperkalaemia with a metabolic acidosis. Absence of cortisol feedback causes high ACTH. Treat with hydrocortisone, plus fludroctisone if primary adrenal failure
• 7
  A 30-year old man presents with bitemporal hemianopia, central obesity and depression. Which investigation is most likely to reveal the underlying endocrine abnormality?
  Difficulty: Medium     Topic: Central obesity and depression
  a

  Oral glucose tolerance test

  b

  Insulin tolerance test

  c

  Midday cortisol measurement

  d

  Synthacthen test

  e

  Dexamethasone suppression test
  Explanation: This man has Cushing's disease, which is Cushing's syndrome due to a pituitary adenoma secreting ACTH. It would be important to do head imaging (CT or MRI head) to visualise the lesion, however this will not characterise the endocrine abnormality. The dexamethasone suppression test measures cortisol before and after high dose steroid. Normally dexamethasone causes strong negative feedback that results in cortisol secretion being suppressed. However in Cushing's disease there is autonomous production therefore cortisol remains high despite the dexamethasone. In addition to testing for diabetes, an oral glucose tolerance test can be used for acromegaly. Normally oral glucose suppresses growth hormone secretion. An insulin tolerance test assess pituitary and adrenal cortex function, normally causing a peak in cortisol. Cortisol can be measured but due to diurnal variation it should be done at midnight when it is normally lowest. The dexamethasone suppression test is used to diagnose Addison's.
• 8
  A 46-year old woman attends the genetics clinic with a history of parathyroid hyperplasia, phaeochromocytoma and medullary thyroid tumour. What is the most likely diagnosis?
  Difficulty: Hard     Topic: Endocrine tumours
  a

  MEN1

  b

  MEN2

  c

  Carney complex

  d

  Von Hippel Lindau syndrome

  e

  Von Recklinghausen's disease
  Explanation: Multiple endocrine neoplasia are a series of autosomal dominant cancer syndromes. MEN1: hyperparathyroidism, endocrine pancreatic tumours, pituitary adenoma. MEN2: medullary thyroid carcinoma (MTC), phaeochromocytoma and parathyroid hyperplasia. Carney complex involves multiple myxomas. Von Hippel Lindau syndrome includes renal cell carcinoma, phaeochromocytoma and haemangiomas. Von Recklinghausen's is neurofibromatosis type 1.
• 9
  A 55-year old man presents with confusion, fatigue, weakness on climbing stairs, polyuria and polydipsia. What is the most likely cause?
  Difficulty: Medium     Topic: Confusion and weakness on stairs
  a

  A pituitary adenoma

  b

  A parathyroid adenoma

  c

  Parathyroid hyperplasia

  d

  Diabetes mellitus

  e

  Diabetes insipidus
  Explanation: Hypercalcaemia affects many systems: confusion or psychosis, nephrolithiasis and polyuria, constipation and abdominal pain and proximal myopathy. The most common cause of hypercalcaemia is a parathyroid adenoma (not hyperplasia). It is treated with surgical resection. Parathyroid hyperplasia is rare in the absence of MEN2. Pituitary adenomas have variable presentations but none match the symptoms. Diabetes mellitus does not present with confusion. Diabetes insipidus does not cause proximal myopathy.
• 10
  A 60-year old woman presents with fatigue, weight gain, bradycardia and cold intolerance. MRI head is normal. Which of the following results is not consistent with the diagnosis?
  Difficulty: Easy     Topic: Cold intolerance with normal MRI
  a

  Low TSH

  b

  Low T4

  c

  Raised serum cholesterol

  d

  Raised MCV

  e

  Anti-thyroid peroxidase antibodies
  Explanation: This woman has primary hypothyroidism (as suggested by a normal MRI), where a low T4 and raised TSH is expected. Low TSH suggests thyrotoxicosis. Hypercholesterolaemia and macrocytic anaemia are also associated. Patients with Hashimoto's thyroiditis initially develop a goitre due to inflammatory infiltration, then become hypothyroid. Anti-thyroid peroxidase enzymes may be found. It is treated with levothyroxine - care should be taken when initiating treatment in elderly patients or those with cardiac disease.
• 11
  A 40-year old woman is about to start treatment on carbimazole. What should she be told?
  Difficulty: Easy     Topic: Carbimazole
  a

  It may cause an initial flare in symptoms

  b

  Go to A&E if she develops any rashes

  c

  If she gets a fever, stop the drug and go to GP

  d

  Long-term treatment may result in lung damage

  e

  The risk of hypothyroidism is low
  Explanation: Carbimazole can cause agranulocytosis in 3/100 patients, which may be life-threatening therefore any signs of infection should be immediately investigated. Overtreatment is common, but is relatively reversible unlikely with radio-ablation. GHRH-agonists (goserelin) in prostate or breast cancer cause an initial increase in symptoms (tumour flare). A severe rash that can develop in some patients on carbamazepine for epilepsy (erythema multiforme or Steven Johnson syndrome). There are several medications that can cause pulmonary fibrosis e.g. methotrexate or amiodarone. There is a significant risk of hypothyroidism with over-treatment using carbimazole.
• 12
  A 56-year old man started treatment for thyrotoxicosis with carbimazole 2 months ago. Pre-treatment his TSH was almost undetectable and now is above the upper limit of normal, what is the most appropriate management?
  Difficulty: Medium     Topic: Thyrotoxicosis treatment
  a

  Investigate for malignancy

  b

  Increase carbimazole

  c

  No change to carbimazole

  d

  Reduce carbimazole

  e

  Discuss radio-iodine ablation
  Explanation: Carbimazole inhibits the action of thyroid peroxidase, therefore blocks iodination of thyroglobulin. If TSH is above normal, it means that too little T3 is reaching the pituitary (the negative feedback is reduced); there is overtreatment so carbimazole should be reduced. Malignancy would be suggested with by a unilateral non-functioning thyroid mass. Radio-iodine would be used if TSH were still very low despite maximum carbimazole.
• 13
  A 41-year old man presents with dizziness and nausea prior to meals. Diagnosis is confirmed by demonstrating raised C-peptide during a 48-hour fast. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Dizziness prior to meals
  a

  Glucagonoma

  b

  Insulinoma

  c

  VIPoma

  d

  Diabetes mellitus

  e

  Diabetes insipidus
  Explanation: Insulinomas are beta-cell tumours that most commonly arise in the pancreas. They cause recurrent hypoglycaemia. Normally insulin secretion (measured by C-peptide) is inhibited by fasting, therefore raised C-peptide during a fast suggests autonomous insulin production. Glucagonomas cause a migratory necrolytic erythema, diarrhoea and weight loss. VIPomas cause profound diarrhoea with loss of all electrolytes. Diabetes insipidus is investigated using the water deprivation test, showing dilute urine the presence of raised serum osmolality.
• 14
  A 43-year old man with type I diabetes develops acute onset double-vision. The right eye appears to be ‘down and out’ with no change in pupil size. Last year he suffered from foot drop, which spontaneously improved. CT head is normal. What is the best term for this condition?
  Difficulty: Easy     Topic: Double-vision in a diabetic
  a

  Motor polyneuropathy

  b

  Diabetic amyotrophy

  c

  Autonomic polyneuropathy

  d

  Mononeuritis multiplex

  e

  Compression neuropathy
  Explanation: Isolated nerve lesions in no particular distribution are termed mononeuritis multiplex. They tend to be of sudden onset and with gradual recovery, in comparison to peripheral sensory neuropathy that is gradual and permanent. CN III palsy with pupillary involvement suggests compression and requires investigation for a posterior communicating artery aneurysm. Amyotrophy causes painful wasting and weakness of proximal leg muscles, usually in middle-aged men with poor glycaemic control.
• 15
  A 47-year old woman presents with postural hypotension, abdominal pain and hyperpigmented mucous membranes. A Synthacthen test is gives no increase in cortisol secretion. What is most likely ABG profile?
  Difficulty: Hard     Topic: Arterial blood gas interpretation 1
  a

  pH = 7.2, pO2 = 13.6 kPa, pCO2 = 3.4 kPa, HCO3- = 18 mmol/L, anion gap = increased

  b

  pH = 7.2, pO2 = 13.6 kPa, pCO2 = 3.4 kPa, HCO3- = 18 mmol/L, anion gap = normal

  c

  pH = 7.2, pO2 = 13.6 kPa, pCO2 = 3.4 kPa, HCO3- = 23 mmol/L, anion gap = increased

  d

  pH = 7.2, pO2 = 13.6 kPa, pCO2 = 3.4 kPa, HCO3- = 23 mmol/L, anion gap = normal

  e

  pH = 7.2, pO2 = 13.6 kPa, pCO2 = 3.4 kPa, HCO3- = 18 mmol/L, anion gap = decreased
  Explanation: This woman has adrenocortical failure - Addison's disease. Due to the failure to excrete potassium, patients develop a metabolic acidosis. The anion gap is normal because a gain of hydrogen ions accounts for the acidosis. Anion gap becomes increased when there is a gain of organic acids or inorganic acids that do not form part of the anion gap calculation e.g. phosphoric acid. 'B' is the only ABG profile consistent with this.
• 16
  A 74-year old lady is being treated with oral hypoglycaemic agents. She experiences intermittent sweating, palpitations and nausea that is relieved by eating. Which medication is most likely to be the cause?
  Difficulty: Medium     Topic: Hypoglycaemic drugs
  a

  Metformin

  b

  Repaglinide

  c

  Exentaide

  d

  Vidagliptin

  e

  Glibenclamide
  Explanation: The woman is having recurrent hypoglycaemic events. Sulfonylureas cause hypoglycaemia but increasing insulin secretion, and this is more common with glibenclamide because it has a long duration of action; caution in prescribing to those at risk of falls or isolated. Metformin does not cause hypoglycaemia. Repaglinide increases insulin secretion but has very short duration of action so low rates of hypoglycaemia. Exenatide and vidagliptin increase insulin release in the presence of food doesn't cause hypoglycaemia.
• 17
  A 45-year old obese man has been treated with metformin for the last 6months. HbA1c = 6.8%. What is the most appropriate next treatment?
  Difficulty: Easy     Topic: Treatment of type 2 diabetes ii
  a

  No changes required

  b

  Increase dose of metformin

  c

  Add gliclazide

  d

  Add repaglinide

  e

  Switch to exenatide
  Explanation: NICE guidance states that treatment is defined as being inadequate when on metformin if HbA1c >7.5%. Therefore this patient needs re-education on diet and exercise but no change to medication. If it were >7.5% then gliclizide should have been added. Repaglinide can be added to metformin plus sulfonylurea. Exenatide can only be used in patients with a BMI of >35kg/m2 with inadequate control on metformin plus sulfonylurea.
• 18
  A 45-year old obese man has been treated with diet and exercise over the last 6months for type 2 diabetes. HbA1c = 8.9%. What is the most appropriate next treatment?
  Difficulty: Easy     Topic: Treatment of type 2 diabetes i
  a

  Glibenclamide

  b

  Metformin

  c

  Repaglinide

  d

  Exenatide

  e

  Acarbose
  Explanation: First line treatment for obese patient with type 2 diabetes is metformin if their HbA1c is >6.5% after 3-6m of initial diet and exercise management. If still inadequate, a sulfonylurea should be added. Next either repaglinide or acarbose can be added, or exenatide used if the criteria are met. Thiazolidinediones are not longer recommended. If the patient is willing, insulin can be started after maximal oral therapy.
• 19
  Which of the following is least associated with diabetes?
  Difficulty: Easy     Topic: Secondary DM
  a

  Pancreatic cancer

  b

  Bendroflumethiazide

  c

  Acromegaly

  d

  Anti-psychotics

  e

  Hepatic cirrhosis
  Explanation: Liver failure is associated with hypoglycaemia because the liver is the only location of glucose-6-phosphatase that allows movement of intracellular glucose into the blood stream. Pancreatic cancer causes islet dysfunction due to pressure build-up through the exocrine system. Thiazides and anti-psychotics (especially atypicals) increase risk of diabetes and the metabolic syndrome. GH exerts many actions through IGF-1, which causes diabetes or insulin-resistance.
• 20
  An 67-year old man presents with only blurring of vision. Which of the further findings below would is required to diagnose diabetes?
  Difficulty: Medium     Topic: Diagnosis of DM
  a

  1x fasting capillary blood glucose >7mmol/L

  b

  1x random venous blood glucose >11.1mmol/L

  c

  2x fasting capillary blood glucose >7mmol/L

  d

  Venous blood glucose >7.9mmol/L 2 hours after a OGTT

  e

  1x fasting venous blood glucose >6.1mmol/L
  Explanation: Diagnosis of DM uses a venous (not capillary) blood glucose of >7mmol/L if fasting, or >11.1mmol/L random or following OGTT. If asymptomatic, 2 readings are required; only 1 is required in this case due the presence of symptoms. Raised venous glucose after OGTT describes impaired glucose tolerance, which is a precursor to type 2 DM and increases cardiovascular risk. Raised fasting glucose, but with a normal OGTT, describes impaired fasting glucose, which has a lower rate of progression to diabetes.
• 21
  A 55-year old lady present with fatigue. On observation she is overweight, has a humped back and abdominal striae. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Humped back and fatigue
  a

  Cushing's syndrome

  b

  Hypothyroidism

  c

  Pan-hypopituitarism

  d

  Acromegaly

  e

  Prader-Willi syndrome
  Explanation: Abdominal striae present in Cushing's are wider and more purple than those following childbirth or weight loss. Humped back occurs due to fat deposition, it is the same cause for the 'moon face' appearance. None of the other conditions cause abdominal striae. Prader-Willi causes obesity due to hyperphagia but not a humped back.
• 22
  A 54-year old woman presents with fatigue. On observation she has coarse facial features, prognathism and macroglossia. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Prognathism and fatigue
  a

  Cushing's syndrome

  b

  B12-deficiency

  c

  Hypothyroidism

  d

  Acromegaly

  e

  Pan-hypopituitarism
  Explanation: Acromegaly is equally common in men and women. Facial features may appear generally coarse, with an enlarged supraorbital ridge in men. Prognathism is protrusion of the mandible beyond the maxilla. Macroglossia occurs, but without the glossitis that is present in B12 deficiency. Hypothyroidism has a characteristic face that can be described as 'toad-like' or mimic depression.
• 23
  A 40-year old lady presents with a history of fatigue. On observation she has hair loss, onycholysis, prominent sclerae and oedematous, erythematous tissue over her shins. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Hair loss and prominent sclerae
  a

  Hypothyroidism

  b

  Hyperthyroidism

  c

  Addison's disease

  d

  Psoriasis

  e

  Acromegaly
  Explanation: Despite seeming counter-intuitive, thyrotoxicosis causes fatigue. Alopecia, onycholysis and proptosis are all features of hyperthyroidism. She has pre-tibial myxoedema, which confusingly is associated with thyrotoxicosis, not hypothyroidism (also known as myxoedema). Psoriasis causes onycholysis but none of the other features.
• 24
  Which of these statements about acromegaly is false?
  Difficulty: Easy     Topic: Acromegaly
  a

  Shoes that do not fit may be a presenting feature

  b

  Osteoarthritis is more likely

  c

  Cardiovascular disease risk is increased

  d

  There may be bilateral loss of nasal visual fields

  e

  Patients become weaker
  Explanation: Acromegaly is a condition of growth hormone excess, almost always due to a pituitary adenoma. Local growth of the adenoma compresses the fibres that decussate at the optic chiasm. These fibres come from the nasal retina therefore there is loss of the temporal visual field (bilateral heteronymous hemianopia). There is soft tissue growth so rings and shoes no longer fit. It increases risk of OA, cardiovascular disease and malignancy. It is associated with a proximal myopathy.
• 25
  A 36-year old hockey player notes her gum guard no longer fits her. An oral glucose tolerance test is used to give the diagnosis. What is the most likely underlying condition?
  Difficulty: Hard     Topic: Non-fitting gum guard
  a

  Cushing's syndrome

  b

  Diabetes mellitus

  c

  ACE-inhibitor side-effect

  d

  Acromegaly

  e

  Nifedipine side-effect
  Explanation: This woman has acromegaly. Enlarging jaw or increased space between teeth are features. Nifedipine causes gingival hypertrophy, however an OGTT was used to give the diagnosis. Normally glucose inhibits growth hormone (GH) secretion in acromegaly, GH remains high. Acromegaly can also cause hypertension. Cushing's causes diabetes but an OGTT does not diagnose Cushing's. DM does not cause gingival hypertrophy. ACEi cause dry cough and reduced renal function.
• 26
  An anxious 26-year old woman is found to have an enlarged left suprarenal gland. She is intermittently hypertensive, complains of palpitations and is of normal weight. What is the most likely diagnosis?
  Difficulty: Medium     Topic: Enlarged surprarenal gland
  a

  Phaeochromocytoma

  b

  Cushing’s syndrome

  c

  Conn’s syndrome

  d

  Addison’s disease

  e

  Renal cell carcinoma
  Explanation: Phaeochromocytoma is a tumour of enterochromaffin cells that most commonly arises in the adrenal medulla, more rarely in the sympathetic chain. It releases monoamines (NA and adrenaline) intermittently causing flushing, anxiety, sweating and abdominal pain. Diagnosis uses 3x 24-hour collection for urinary catecholamines. Cushing's would cause obesity. Conn's syndrome causes constant hypertension. Addison's causes hypotension. Renal cell carcinoma can cause hypertension and mass would be seen in the kidney.
• 27
  A 25-year old diabetic man attends A&E feeling very unwell. He has had gastroenteritis for 2 days and says he feels even worse today. What is most likely ABG profile?
  Difficulty: Medium     Topic: Arterial blood gas interpretation 2
  a

  pH = 7.1, pO2 = 13.4 kPa, pCO2 = 5.1 kPa, HCO3- = 16 mmol/L, anion gap = increased

  b

  pH = 7.1, pO2 = 13.4 kPa, pCO2 = 2.4 kPa, HCO3- = 16 mmol/L, anion gap = decreased

  c

  pH = 7.1, pO2 = 13.4 kPa, pCO2 = 2.4 kPa, HCO3- = 16 mmol/L, anion gap = normal

  d

  pH = 7.1, pO2 = 13.4 kPa, pCO2 = 5.1 kPa, HCO3- = 16 mmol/L, anion gap = normal

  e

  pH = 7.1, pO2 = 13.4 kPa, pCO2 = 2.4 kPa, HCO3- = 16 mmol/L, anion gap = increased
  Explanation: At 25-years old, a diabetic is most likely to be type 1, therefore at is at risk of DKA during intercurrent illness. DKA results in a metabolic acidosis with raised anion gap due to the presence of acidic ketones (beta-hydroxybutyrate, acetone and acetaldehyde). Ketones are produced because in the absence of insulin there is greatly increased lipolysis. There is build-up of acetyl-CoA from fatty acid metabolism, which is used to generate acidic ketones that supply the brain. 'E' is the only profile consistent with this.