An unusual presentation of a right atrial Chiari network.

In 1897, the anatomist Chiari described a structure in the right atrium connected to the Eustachian valve identified as the embryological vestige of the right valve of the sinus venosus. The discovery of a mass in the right atrium obliges the clinician to perform a broad differential diagnosis among a tumour, vegetations on the tricuspid valve, an atrial thrombus and Chiari network. We present a case of Chiari network in a 55-year-old Italian woman.