Donald O. Castell first described his sign in the 1967 paper, “The Spleen Percussion Sign” published in Annals of Internal Medicine. Castell, a George Washington Medical School graduate, is also a Navy-trained gastroenterologist. While stationed at the Great Lakes naval base in northern Illinois, Castell studied 20 male patients, 10 of whom had a positive percussion [Castell's] sign and 10 patient controls with negative percussion signs.
In 1967, Donald O. Castell, a gastroenterologist trained by the Navy, described his spleen percussion sign in the Annals of Internal Medicine. He studied 20 male patients at Great Lakes naval base, finding that 10 had the positive sign and 10 did not.