The Health Service Executive is to review the files of more than 3,000 breast cancer patients who attended the Midlands Regional Hospital in Portlaoise over a four-year period.
3,000 mammograms and 2,500 breast ultrasounds will be re-examined.
This is the latest in a series of such reviews established in recent months.
Last May, 28 cases relating to the laboratories at Cork University Hospital were reviewed when it was discovered a woman with breast cancer was wrongly given the all clear.
While last month, procedures at the pathology laboratory in University Hospital Galway were examined when it was discovered a similar situation had occurred there.
And it has also been confirmed that the cases of ten women attending the private Barringtons Hospital in Limerick will be reviewed.
The HSE has moved to reassure women, however one leading oncologist has criticised plans to increase the number of hospitals providing cancer care services.
Prof John Crowne of St Vincent's Hospital in Dublin says increasing the number of centres is a major blunder and will reduce the quality of service provided to cancer patients.
Patient Focus has called on the HSE and the Department of Health to put in place a support process for all those affected by patient care issues at Barringtons Hospital and the Midlands Regional Hospital in Portlaoise.
The Action Breast Cancer Helpline is 1800-309040 (office hours only)
The Midland Regional Hospital in Portlaoise has set up its own helpline for women who have concerns in relation to mammography or breast ultrasounds carried out there.
The Midland Regional Hospital helpline is 1800-252041 (office hours only)
