Joseph Carey Merrick, the 19th-century Englishman known as the Elephant Man, suffered from Proteus syndrome, explains About.com. Named after a Greek god who could change forms, the rare disorder is characterized by overgrowth of one side of the body, abnormally large hands or feet, and darkened growths on the skin.
Joseph Merrick lived from 1862 to 1890, and during his time, doctors believed he suffered from elephantiasis, a lymphatic disorder that causes body parts to severely swell, states About.com. By 1976, doctors changed his diagnosis to neurofibromatosis, a disorder in which tumors grow on the nervous system. It wasn't until 1996, over 100 years after his death, that CT scans of Merrick's skeleton determined that Proteus syndrome was the correct diagnosis.