Cystic tumour of the atrioventricular node: three cases of sudden death.

Cystic tumour of the atrioventricular nodal region is a rare primary cardiac tumour that can cause sudden death. Antemortem diagnosis and successful excision of this type of tumour are extremely rare. Three cases of sudden death are reported: A 25- and 40-year-old with a history of heart block and a 60-year-old with no medical history. There have been more than 120 cases of sudden death attributed to primary cardiac tumours in the literature. Although over 100 of these lesions were histologically benign, their intracardiac locations precipitated conductive and haemodynamic abnormalities that resulted in sudden death. The most common intracardiac lesion causing sudden death, cystic tumour of the atrioventricular node, however, may not be discovered unless the atrioventricular node is microscopically examined.