MRCPUK Endocrinology and Diabetes (Specialty Certificate Examination) Sample Questions:

1. A 26-year-old woman was urgently referred to clinic with a 6-week history of retroorbital headaches and deteriorating vision. Her past medical history was unremarkable, although on questioning she admitted that she had recently found it increasingly difficult to cope with her busy job.
On examination, her pulse was 60 beats per minute and regular, and her blood pressure was 110/75 mmHg lying and 90/60 mmHg standing. She was pale and had dry skin. Visual acuities were reduced (6/12 right; 6/24 left), and she had a bitemporal inferior quadrantanopia.
Investigations:
serum sodium132 mmol/L (137-144) serum potassium4.0 mmol/L (3.5-4.9)
short tetracosactide Synacthen@ test (250 micrograms): serum cortisol (30 min after tetracosactide)185 nmol/L (>550)
plasma follicle-stimulating hormone2.7 U/L plasma luteinising hormone3.5 U/L serum prolactin1050 mU/L (<360) serum thyroid-stimulating hormone0.3 mU/L (0.4-5.0) serum free T48.0 pmol/L (10.0-22.0)
serum insulin-like growth factor 14.7 nmol/L (7.5-37.3)
MR scan of brainsee image

What is the most likely diagnosis?

A) non-functioning pituitary adenoma
B) craniopharyngioma
C) autoimmune hypophysitis
D) Rathke's cleft cyst
E) prolactinoma

2. A 56-year-old woman presented with a swelling in her neck, which she had noticed by chance 6 weeks previously. The swelling had not changed in size since she first noticed it, and was completely asymptomatic.
On examination, there was a smooth nodule in the thyroid that moved up on swallowing and there was no lymphadenopathy.
Investigations:
ultrasound scan of thyroidsingle 4.7-cm hypoechoic nodule
in upper left lobe
serum thyroid-stimulating hormone0.8 mU/L (0.4-5.0)
What is the most appropriate next step in management?

A) fine-needle aspiration for cytology
B) serial ultrasound examinations
C) isotope uptake scan
D) FDG-PET CT scan
E) hemithyroidectomy

3. A 43-year-old man presented with a 2-year history of tiredness and reduced libido. He had not been found to have diabetes mellitus.
On examination, his body mass index was 22.4 kg/m2 (18-25), he was poorly virilised and had 10 mL testes.
Investigations:
serum cortisol (09.00 h)220 nmol/L (200-700) serum testosterone4 nmol/L (9.0-35.0) plasma follicle-stimulating hormone1.2 U/L (1.0-7.0) plasma luteinising hormone1.2 U/L (1.0-10.0) serum prolactin150 mU/L (<360) serum thyroid-stimulating hormone1.2 mU/L (0.4-5.0) serum free T48.2 pmol/L (10.0-22.0)
serum insulin-like growth factor 17.8 nmol/L (5.6-23.3)
MR scan of pituitaryempty sella; no mass lesion
An insulin tolerance test was advised to assess both cortisol and growth hormone reserve.
What is the most appropriate dose of insulin (in units/kg body weight) to administer?

A) 1.0
B) 0.1
C) 0.5
D) 0.05
E) 0.01

4. A 32-year-old man presented with persistent thirst. He had a past history of polydactyly, which had been corrected surgically in infancy. His family had remarked about his recent weight gain. His only concern was of blurring of vision and difficulty reading. His father and paternal grandfather had each developed type 2 diabetes mellitus when aged 41 and 56 years, respectively.
His body mass index was 34 kg/m2 (18-25). Urinalysis showed glucose 2+, ketones 1+.
Investigations:
serum sodium142 mmol/L (137-144)
serum potassium3.8 mmol/L (3.5-4.9)
serum chloride105 mmol/L (95-107)
serum urea5.0 mmol/L (2.5-7.0)
serum creatinine90 umol/L (60-110)
haemoglobin A1c91 mmol/mol (20-42)
random plasma glucose11.3 mmol/L
ultrasound scan of kidneysnormal
What is the most likely underlying diagnosis?

A) Bardet-Biedl syndrome
B) type 2 diabetes mellitus
C) monogenic diabetes caused by a mutation in the glucokinase gene
D) Prader-Willi syndrome
E) monogenic diabetes caused by a mutation in the HNF-1? gene

5. Carbimazole is routinely used in the management of thyroid disease.
What does carbimazole inhibit?

A) thyroid peroxidase
B) deiodinase type 1
C) presentation of thyroid antigens to autoreactive T cells
D) thyroglobulin synthesis
E) sodium/iodide symporter

Solutions: