American physician (1837–1932) who performed the first removal of a brain tumor in the United States and pioneered the adoption of Lister’s antiseptic surgical practices. He assisted Dr. Joseph Bryant in the now-famous secret operation to remove a cancerous tumor from the jaw of President Grover Cleveland aboard a yacht on July 1, 1893. TLS signed “W. W. Keen,” one page, 7 x 7.75, personal letterhead, March 13, 1889. Letter to a woman discussing her medical condition. In part: “I find on looking at the notes that there is no account of what troubles were produced by your loose kidney. Will you be good enough to tell me what discomforts, pains etc. were produced, and whether you had any vomiting or palpitation of the heart.” At the conclusion of the letter, Keen writes, “How have you been since the operation?” Double matted and framed with the original mailing envelope, a portrait of Keen, and a printed caption, to an overall size of 19 x 16. In fine condition, with intersecting folds, one through a single letter of signature, a partial separation along one fold, and light overall toning. An interesting letter with highly desirable medical content. RRAuction COA.