A statement from the Hotel Dieu Hospital said Dr. Barbara Heartwell was withdrawing from surgery while her history is reviewed, the Windsor Star reported.
Last week it emerged Heartwell, with 28 years experience, mistakenly removed a woman's breast in November after misreading her files and overlooking a benign diagnosis.
Tuesday, another woman came forward, saying Heartwell admitted to her in 2001 she had removed her breast and lymph nodes by mistake, the report said. That woman, Janice Laporte, sued Heartwell, but it was settled out of court and a confidentially agreements prevents details from being revealed, the Star said.
There was no indication if the most recent patient is pursuing legal action.
Hospital Chief Executive Officer Warren Chant said in a statement Heartwell had voluntarily withdrawn from surgical duties.
"The hospital is deeply troubled by these incidents and is firmly resolved to fully investigate and take whatever measures are required," Chant said.