Cystic tumour of the atrioventricular nodal region is a very rare tumour of the heart in the region of the atrioventricular node.

It is also known as mesothelioma of the atrioventricular node.

[1] Cystic tumours of the atrioventricular nodal region, true to their name, have cystic spaces, which are lined by a single layer of histomorphologically benign epithelial cells.

The appearance is similar to that of lymphangioma and this is a name that has been used for this tumour.

[1] The treatment of cystic tumours of the atrioventricular nodal region is surgical excision.