Ball-thrombus of the right atrium.

A -study of reported cases reveals that while the occurrence of ball-thrombus of the left atrium is unusual a ball-thrombus of the right atrium is very rare indeed. The first case report is that of McLeod, in 1883, and sixty-one years elapse before the next-that of Wright, Flynn, and Druet, in 1944. Radding in America and Moia et al. in Argentina each published a report of a case in 1951, and the latter refer to an unpublished thesis by Romano of Buenos Aires (1944), in which a further case is described. As only five examples have apparenty been reported up to the present, it is thought of interest to record a sixth. On correlating the histories and clinical findings, a distinct picture emerges; indeed, it may be possible to make an ante-mortem diagnosis of ball valve obstruction of the tricuspid valve, as actually occurred in the case of Wright et al. (1944); whether or not it is due to a thrombus, however, and whether this thrombus is free or attached, cannot be clinically ascertained.