Most of us recall lobotomies as they were depicted in the movie “One Flew over the Cuckoo’s Nest”— horrifying operations inappropriately used to control mentally ill patients. But in the 1950s, surgeons also used them to treat severe pain from cancer and other diseases.

Now a Yale researcher has uncovered surprising new evidence of a famous patient who apparently received a lobotomy for cancer pain during that time: Eva Perón, the first lady of Argentina, who was known as Evita. The story is an interesting, sad footnote in the history not only of lobotomy, but of pain control.

The nature of Perón’s illness was initially shrouded in silence. Her doctors diagnosed advanced cervical cancer in August 1951, but as was common at the time, the patient was told only that she had a uterine problem. According to the biographers Nicholas Fraser and Marysa Navarro, secrecy was so paramount that an American specialist, Dr. George Pack, performed Perón’s cancer operation without her or the public ever knowing. He entered the operating suite after she was under anesthesia....