Difficult Questions Part 4

Front 1

A diagnosis of diabetes mellitus was being considered in a 32-year-old woman who was 16 weeks pregnant. Her body mass index was 22 kg/m2 (18–25).
Investigations:
oral glucose tolerance test (75 g):
baseline plasma glucose 6.0 mmol/L (3.0–6.0)
2-h plasma glucose 12.5 mmol/L (<7.8)
What is the most appropriate next step in management

Question 26
A: prescribe metformin
B: prescribe oral glipizide
C: prescribe soluble insulin
D: recommend low-calorie diet
E: repeat oral glucose tolerance test in 4 weeks

Back 1

Answer C

Front 2

A 16-year-old boy with type 1 diabetes mellitus was treated with a biphasic insulin preparation but achievement of good blood glucose control proved difficult. He was offered treatment with the insulin analogue, insulin lispro.
Which characteristic of insulin lispro might improve his glycaemic control
Question 64
A: low incidence of hypoglycaemia
B: low incidence of lipoatrophy at the injection site
C: low risk of immunogenic reaction
D: rapid onset of action
E: small injection volume

Back 2

Answer- D) Rapid onset of action

Front 3

A 58-year-old man with congestive heart failure remained oedematous despite treatment with furosemide 120 mg daily.
Investigations:
serum sodium 134 mmol/L (137–144)
serum potassium 3.4 mmol/L (3.5–4.9)
serum urea 10.6 mmol/L (2.5–7.0)
serum creatinine 156 µmol/L (60–110)
What is most likely to be present
Question 72
A: high plasma aldosterone concentration
B: high serum cortisol concentration
C: low plasma angiotensin II concentration
D: low plasma atrial natriuretic peptide concentration
E: low plasma renin concentration

Back 3

Answer- A) High plasma aldosterone

Front 4

A 35-year-old woman presented with a 6-month history of episodes of sweating, joint pain and headaches.
On examination, her blood pressure was 160/90 mmHg. A clinical diagnosis of acromegaly was suspected.
Investigations:
fasting plasma glucose 8.1 mmol/L (3.0–6.0)
What additional investigation would confirm the diagnosis
Question 79
A: fasting growth hormone
B: growth hormone suppression test
C: insulin-like growth factor 1
D: insulin tolerance test
E: MR scan of pituitary

Back 4

Answer- B)

Front 5

A 77-year-old man presented with increasing pains around the low back and lower limb
girdle. He had recently presented with symptoms of hesitancy and post-micturition
dribbling.

Investigations:

erythrocyte sedimentation rate 28 mm/1st h (<20)

serum corrected calcium 2.34 mmol/L (2.20–2.60)
serum phosphate 0.8 mmol/L (0.8–1.4)
serum alkaline phosphatase 2985 U/L (45–105)

serum prostate-specific antigen 6 μg/L (<4)

What is the most likely cause of this man’s pain

A insufficiency fracture of the pelvis
B osteomalacia
C Paget’s disease of the pelvis
D polymyalgia rheumatica
E prostatic carcinoma with metastases

Back 5

Answer- C

Front 6

A 20-year-old woman presented 24 hours after taking an overdose of 80 tablets of thyroxine
100 μg. On examination, she was clinically euthyroid.

What is the most appropriate treatment

A -adrenoceptor blockade
B forced alkaline diuresis
C haemodialysis
D no treatment
E stomach washout

Back 6

Answer – D

Front 7

A 67-year-old woman was referred with a 3-month history of painful legs, malaise and weight
loss. She had had type 2 diabetes mellitus and hypertension for 18 years. Her medication
was gliclazide 160 mg twice daily, ramipril 2.5 mg daily and atorvastatin 20 mg daily.
On examination, her blood pressure was 145/90 mmHg. There was some tenderness over
her spine and lower legs.
Investigations:
serum sodium 138 mmol/L (137–144)
serum potassium 5.5 mmol/L (3.5–4.9)
serum creatinine 240 μmol/L (60–110)
serum corrected calcium 1.80 mmol/L (2.20–2.60)
serum phosphate 1.6 mmol/L (0.8–1.4)
plasma parathyroid hormone 22.2 pmol/L (0.9–5.4)
What therapy is most likely to correct the calcium and parathyroid hormone concentrations
A alendronic acid
B alfacalcidol
C calcitonin
D cinacalcet
E ergocalciferol

Back 7

Answer- B = Alpha Calcidiol

Front 8

A 42-year-old man was admitted to hospital with severe abdominal pain. His alcohol intake
was 18 units per week. His serum amylase level was raised at 1346 U/L (60–180) and a
diagnosis of acute pancreatitis was made.
There was no evidence of gallstones. He made an uncomplicated recovery.
Investigations (after recovery):
fasting plasma glucose 5.7 mmol/L (3.0–6.0)
serum cholesterol 5.8 mmol/L (<5.2)
serum LDL cholesterol 3.41 mmol/L (<3.36)
serum HDL cholesterol 0.96 mmol/L (>1.55)
fasting serum triglycerides 22.63 mmol/L (0.45–1.69)
What is the most appropriate treatment to reduce his risk of recurrent pancreatitis
A atorvastatin
B ciprofibrate
C ezetimibe
D nicotinic acid
E omega-3-marine triglycerides

Back 8

Answer Key: B Ciprofibrate

Front 9

A 58-year-old heavy-goods vehicle driver presented to his general practitioner with thirst and
nocturia. He had a past history of chronic renal failure, ischaemic heart disease and left
ventricular failure. He was taking bisoprolol, aspirin, pravastatin, ramipril, spironolactone and
furosemide. His body mass index was 35 kg/m2 (18–25).
Investigations:
serum creatinine 230 μmol/L (60–110)
fasting plasma glucose 17.0 mmol/L (3.0–6.0)
haemoglobin A1c 10.5% (3.8–6.4);
91mmol/mol (20–40)
A diagnosis of type 2 diabetes mellitus was made. He was seen by the practice nurse and
taught urine testing. The dietitian gave him advice on a diabetic diet.
At review 6 weeks later, he complained that he felt no better. His urine tests continued to
show glucose 3+, despite his adherence to his diabetic diet.
What is the most appropriate additional treatment
A acarbose
B glibenclamide
C insulin
D metformin
E pioglitazone

Back 9

Answer Key: C
Correct answer: C
Explanation
This patient remains symptomatic from diabetes despite an adequate trial of diet. Because of his renal impairment and heart failure, metformin is contraindicated. Glibenclamide should be avoided for the same reason as it is renally excreted. Pioglitazone is safe in renal failure but cannot be used in patients with heart failure. Acarbose should not be used if eGFR is < 25 ml/min/1.73m2 (this patient has an eGFR of 27) and is not well tolerated. Insulin is therefore the correct answer.

Front 10

A 75-year-old man presented to his general practitioner with worsening palpitations and dyspnoea on exercise. He had lost about 3 kg in weight during the past 2 months. He had developed a coarse tremor in both hands. His past medical history included ischaemic heart disease and recurrent supraventricular tachycardia. He was taking aspirin 75 mg daily, simvastatin 40 mg daily, bisoprolol 5 mg daily, ramipril 10 mg daily, amiodarone 200 mg daily, glyceryl trinitrate spray as required, and warfarin.
On examination, there was a small palpable goitre. He had a tremor, warm hands, bilateral upper eyelid retraction and proptosis.
Investigations:
serum thyroid-stimulating hormone <0.1 mU/L (0.4–5.0)
serum free T4 95.0 pmol/L (10.0–22.0)
serum free T3 35.2 pmol/L (3.0–7.0)
ECG sinus tachycardia
What is the most likely cause of this patient’s thyroid dysfunction
A amiodarone-induced thyrotoxicosis
B Graves’ disease
C Reidel’s thyroiditis
D solitary toxic nodule
E toxic multinodular goitre

Back 10

Answer- B – Grave’s disease

Front 11

A 73-year-old retired man was admitted after he had been found to have renal impairment by his general practitioner. He gave a 3-month history of lethargy and back pain, with thirst and constipation over the past 4 weeks. He had noticed that he had passed less urine than usual in the past 3 days.
Abdominal examination was normal.
Investigations:
haemoglobin 98 g/L (130–180)
white cell count 5.6 × 109 /L (4.0–11.0)
platelet count 380 × 109 /L (150–400)
erythrocyte sedimentation rate 115 mm/1st h (<20)

serum urea 36.3 mmol/L (2.5–7.0)
serum creatinine 651 μmol/L (60–110)
serum corrected calcium 2.92 mmol/L (2.20–2.60)
serum total protein 85 g/L (61–76)
serum albumin 34 g/L (37–49)
serum alkaline phosphatase 99 U/L (45–105)
What is the most likely diagnosis
Answers
• A: carcinoma of prostate
• B: myeloma
• C: primary hyperparathyroidism
• D: sarcoidosis
• E: tuberculosis

Back 11

Correct answer: B
Explanation
This man has severe renal failure with hypercalcaemia and high serum globulins (high serum total protein, low serum albumin). He is also anaemic and has a very high erythrocyte sedimentation rate. These features are highly suggestive of myeloma, and the history of diminished urine output probably indicates development or progression of cast nephropathy.
Carcinoma of prostate with bone metastases and primary hyperparathyroidism may cause hypercalcaemia but usually not high serum globulins, and this level of hypercalcaemia alone is unlikely to cause severe renal failure. The normal serum alkaline phosphatase also makes these conditions less likely. Sarcoidosis may cause hypercalcaemia, high serum globulins, renal failure anaemia and a high erythrocyte sedimentation rate but it is much less common than myeloma in this age group. Tuberculosis rarely causes hypercalcaemia or renal failure.

Front 12

A 56-year-old man was referred to the medical clinic from the psychiatric unit because of weight gain of 20 kg over 4 months. He had a 6-month history of severe depression with psychosis, which had required inpatient treatment. He was taking olanzapine 20 mg daily and fluoxetine 40 mg daily.
On examination, he appeared cushingoid, with centripetal obesity and a few abdominal striae. He had reasonable proximal muscle strength. His blood pressure was 170/100 mmHg.
Investigations:
fasting plasma glucose 8.5 mmol/L (3–6)
serum cholesterol 6.4 mmol/L (<5.2)
serum LDL cholesterol 5.01 mmol/L (<3.36)
serum HDL cholesterol 0.75 mmol/L (>1.55)
fasting serum triglycerides 2.42 mmol/L (0.45–1.69)
overnight dexamethasone suppression test (after 1 mg dexamethasone):
serum cortisol 55 nmol/L (<50)
24-h urinary free cortisol 310 nmol (55–250)
What is the most likely diagnosis
Answers
• A: adrenal Cushing’s syndrome
• B: ectopic ACTH syndrome
• C: metabolic syndrome
• D: pituitary-dependent Cushing’s disease
• E: pseudo-Cushing’s syndrome

Back 12

Correct answer: E
Explanation
This man has many features of Cushing’s syndrome on a background of severe depression. Depression is a common feature of Cushing’s but is usually more agitated than psychotic in type. The almost complete suppression of serum cortisol by low dose dexamethasone excludes both adrenal Cushing’s and ectopic ACTH syndrome. Around 8% of patients with proven pituitary Cushing’s disease will suppress serum cortisol with a low dose suppression test, but the minimally elevated urinary cortisol makes this diagnosis less likely (levels should be > 3 times normal for definitive diagnosis). There is considerable overlap between the appearances of Cushing’s and the metabolic syndrome but the history of depression and the investigations make pseudo-Cushing’s the most likely diagnosis.

Front 13

A 57-year-old woman, who lived alone, was found in a confused state by neighbours and brought to hospital.
On examination, her temperature was 36.8°C, her pulse was 120 beats per minute and her blood pressure was 90/60 mmHg. There was no focal neurological deficit. Fundoscopy was normal.
Investigations:
haemoglobin 139 g/L (115–165)
white cell count 9.1 × 109/L (4.0–11.0)
platelet count 390 × 109/L (150–400)

serum sodium 131 mmol/L (137–144)
serum potassium 5.2 mmol/L (3.5–4.9)
serum urea 12.3 mmol/L (2.5–7.0)
serum creatinine 132 μmol/L (60–110)
serum corrected calcium 3.40 mmol/L (2.20–2.60)
serum total bilirubin 17 μmol/L (1–22)
serum alanine aminotransferase 129 U/L (5–35)
serum alkaline phosphatase 643 U/L (45–105)
serum gamma glutamyl transferase 80 U/L (4–35)
What is the most likely cause of the hypercalcaemia
Answers
• A: Addison’s disease
• B: myeloma
• C: Paget’s disease of bone
• D: primary hyperparathyroidism
• E: skeletal metastases

Back 13

Correct answer: E
Explanation
This individual has presented with confusion, tachycardia and hypotension. The investigations confirm a normal full blood count, renal impairment, significant hypercalcaemia and abnormal liver biochemistry.
It is most likely that the hypercalcaemia has resulted in the confusion and dehydration, leading to the presenting signs and symptoms.
The abnormal liver biochemistry would be unusual in myeloma. Paget’s disease usually causes an isolated rise in the alkaline phosphatase, and hypercalcaemia is unusual. Addison’s disease is characterised by hyponatraemia in 85–90% of individuals and hyperkalaemia in 60–65%, but hypercalcaemia is a rare occurrence.
It is therefore most likely that this individual has metastatic cancer, with liver involvement (resulting in the abnormal liver biochemistry) and skeletal metastases (resulting in the hypercalcaemia). The most likely primary sites are breast and lung.