The Health Service Executive has begun informing about 8,000 women who received breast implants about the risk of contracting a rare form of cancer.
It says the women should be aware of the signs and symptoms of breast implant associated with anaplastic large cell lymphoma (BIA-ALCL), a cancer of the immune system (and not a breast cancer).
BIA-ALCL is rare, with a low risk to people with breast implants, and when diagnosed and treated early it has a very good recovery rate, according to the HSE.
Most cases of BIA-ALCL have been in-patients with implants or who have had tissue expanders manufactured by Allergan, with a surface called Biocell. These implants and expanders have not been used in Ireland since December 2018 and no case has as yet been reported here.
The letter advises women with implants to be on the lookout for a swelling felt as a substantial change in the size of the affected breast, which comes on rapidly over several days or weeks. More rarely, it says, there is a lump beside the breast implant, which may or may not be associated with lumps or glands in the armpit on the same side.
Fluid can collect around a breast implant for reasons other than BIA-ALCL, including as part of the healing process after surgery, the HSE advises.
"The purpose of the letter is to inform people about this condition, and to ensure that individuals with implants are familiar with the symptoms and signs so they know when they should go and get a check-up," said HSE national clinical advisor Dr Vida Hamilton. "If you have no symptoms or signs there is no need for any action on your part."
The advice from international medical experts is that women do not need to have their implants removed except as part of the treatment for the condition, she said.
Women who are displaying symptoms of the condition and are unable to contact their hospital or surgeon are advised to go to their GP.