Histories
Herodotus
Herodotus. Godley, Alfred Denis, translator. Cambridge, MA; London: Harvard University Press; William Heinemann, Ltd., 1920-1925 (printing).
When the Egyptian physicians who until now had attended the king were about to be impaled for being less skilful than a Greek, Democedes interceded with the king for them and saved them; and he saved an Elean seer, too, who had been a retainer of Polycrates' and was forgotten among the slaves. Democedes was a man of considerable influence with the King.
A short time after this, something else occurred; there was a swelling on the breast of Atossa, the daughter of Cyrus and wife of Darius, which broke and spread further. As long as it was small, she hid it out of shame and told no one; but when it got bad, she sent for Democedes and showed it to him.