OSAKA — Two women had their breasts removed by a surgeon at a hospital in Hirakata, Osaka Prefecture, in 1996 and 1998 even though pathological tests showed that their tumors were not cancerous, it was learned Thursday.

The 69-year-old surgeon was chief doctor at Hirakata Municipal Hospital at the time of the incidents and is currently an honorary president of the institution.

Medical records of one of the patients were tampered with to conceal the results of the pathological tests, hospital officials added.