Rare case of squamous metaplasia arising in the endocardium of a previous biopsy site in a cardiac transplant recipient as a reparative response

To the Editor,
Cardiac transplantation remains the gold standard therapy for advanced heart failure. The orthotopic technique is employed by virtually all transplant centres, in which the recipient's heart is removed and replaced by donor organ. The contribution of pathology to the success of cardiac transplantation is well established. Cardiac transplant recipients are routinely monitored for rejection by endomyocardial biopsies (EMB) of the right ventricle. EMB is typically performed under local anaesthesia by passing a bioptome through the right internal jugular vein across the tricuspid valve and into the right ventricle. Sampling is usually performed on the fluoroscopic guidance along the interventricular septum. The biopsy material usually includes endocardium and myocardium with endocardium representing endothelial lined tissue with underlying bundles of smooth muscle and connective tissue and myocardium representing myocytes, interstitium and small intramyocardial blood vessels. Repeated biopsy of the same area of the right ventricle gives rise to changes, which include haemorrhage, granulation tissue formation, scarring and an associated inflammatory response. We describe a rare case of squamous metaplasia arising in the endothelium of an EMB resulting from repeated biopsy of the same site...