From Letters of Note, this incredible letter written in 1855 by Lucy Thurston, a 60-year-old missionary in Hawaii who had breast cancer. She underwent a mastectomy (and lymph node removal) with no anesthesia, no blood transfusion.
She wrote the following letter to her daughter a month later and described the unimaginably harrowing experience. The procedure was a success. Lucy Thurston lived for another 21 years.
[WARNING: not for the squeamish]: Letters of Note: “Deep sickness seized me”.
(thanks, @scanman)