A 33-year-old woman was reviewed in the insulin pump clinic. She had had type 1 diabetes mellitus for 10 years. She had been treated with a continuous subcutaneous insulin infusion 3 years previously, because of frequent hypoglycaemic episodes. She had recently undergone continuous glucose monitoring (see image).

Investigations:

haemoglobin A1c43 mmol/mol (20–42)

What is the most likely cause of the blood glucose trace seen between 08.00 h and 10.00 h?

A 56-year-old man presented with a 6-month history of erectile dysfunction. He had noticed a gradual reduction in his frequency of shaving from daily to twice a week. His libido had diminished and he felt that he was not as strong as he once was. He also described general aches and pains. He was a farm worker and had drunk a bottle of vodka daily for several years, but had stopped drinking 2 years previously. He was a non-smoker.

Investigations:

serum urea6.2 mmol/L (2.5–7.0)

serum creatinine89 µmol/L (60–110)

serum albumin40 g/L (37–49)

serum total bilirubin17 µmol/L (1–22)

serum alanine aminotransferase48 U/L (5–35)

serum aspartate aminotransferase37 U/L (1–31)

haemoglobin A1c55 mmol/mol (20–42)

serum cortisol (09.00 h)389 nmol/L (200–700)

serum testosterone0.7 nmol/L (9.0–35.0)

plasma follicle-stimulating hormone2.1 U/L (1.0–7.0)

plasma luteinising hormone2.4 U/L (1.0–10.0)

serum prolactin458 mU/L (<360)

serum thyroid-stimulating hormone3.4 mU/L (0.4–5.0)

MR scan of pituitarysee image

What is the most likely explanation of his symptoms?

A 48-year-old woman presented with a 2-year history of weight gain, easy bruising and mood disturbance.

Investigations:

fasting plasma glucose6.9 mmol/L (3.0–6.0)

low-dose dexamethasone suppression test (2 mg/day for 48 h):

serum cortisol200 nmol/L (<50)

24-h urinary free cortisol (?3)670, 400 and 300 nmol (55–250)

plasma adrenocorticotropic hormone (09.00 h)25.0 pmol/L (3.3–15.4)

MR scan of pituitarynormal

What test is most likely to give a definitive diagnosis?