The Grinch’s heart grew three sizes when he finally learnt the true meaning of Christmas.

But it was an “extremely rare anomaly”, not a potent mix of festive cheer and personal growth (the figurative kind), that was to blame for a middle-aged patient’s massive cardiomegaly.

In fact, it grew so large it filled his entire chest, stealing the show (not Christmas) in BMJ Case Reports.

Featured as its most-read case, the patient had presented with a six-month history of worsening dyspnoea.