The tale of spring water cysts: a historical outline of surgery for congenital pericardial diverticula and cysts.

Congenital pericardial diverticula and cysts are extremely uncommon lesions within the anterior mediastinum. Both lesions derive from the pericardial celom and represent different stages of a common embryogenesis. Initial reports date from the 19th century. Surgical pioneers were Otto Pickhardt, who removed a pericardial cyst at Lenox Hill Hospital in New York in 1931, and Richard Sweet, who accomplished the first resection of a pericardial diverticulum at Massachusetts General Hospital in Boston in 1943. These lesions were also called spring water cysts because they usually contain watery, crystal-clear fluid. This history outlines the milestones of evolving surgical management, from the first report in 1837 up to the present time.