MRCP2-2496
A 35-year-old man presents with breathlessness on exertion of 3 months’ duration. He is usually fit and relatively athletic and now needs to stop for breath on climbing a single flight of stairs.
His general practitioner has arranged investigations for possible renal stones, and he completed a 6-month course of warfarin for deep vein thrombosis (DVT) in the last year, but otherwise, he has no significant previous medical history.
Examination shows pale conjunctivae and a pulse of 100 bpm; heart sounds are normal, and the jugular venous pressure is not raised.
Investigations reveal the following:
Haemoglobin (Hb) 63 g/l 135–175 g/l
White cell count (WCC) 2.5 × 109/l 4.0–11.0 × 109/l
Neutrophils 1.1 × 109/l 2.5–7.58 × 109/l
Platelet (PLT) 75 × 109/l 150–400 × 109/l
Mean corpuscular volume (MCV) 80 fl 80–100 fl
Reticulocytes 90 × 109/l 25–85× 109/l
Blood film Marked anisocytosis, with polychromasia and hypochromatic cells
Ferritin 10 μg/l 20–250 µg/l
Urine dipstick Blood+++
Mid-stream urinalysis No cells
Urine culture Negative
What is the most likely diagnosis?