Crumlin Children's Hospital in Dublin is being urged to conduct an immediate review of all tests for a cancer gene carried out over the past decade.
It comes after a woman was mistakenly given the all-clear.
The woman, who does not want to be identified, was told in 2009 that she tested negative for the BRCA1 gene.
However, last month, it emerged her test result was incorrect and her doctors were told last month that she actually tested positive.
She is now being treated for an aggressive form of ovarian cancer.
The Sunday Times reports the woman now wants Crumlin Children's Hospital to conduct a review of all BRCA genetic tests to ensure no other patients were given incorrect results.
In a statement issued through her solicitor, the woman says she is now in a "grave situation" and that the incorrect result will have life-altering consequences for her.
The hospital declined to make any comment when contacted by the paper.
Róisín Shortall, the co-leader of the Social Democrats, said there is now a need to find out how the error happened and whether any other women have been affected.
In a statement, Deputy Shortall said: "It’s vital that all women who have undergone the same test are contacted immediately and provided with clear and accurate information about where they stand.
“The Minister for Health and the HSE must move swiftly to review the test results of all women who have undergone BRCA tests at Our Lady’s Children’s Hospital Crumlin in the past decade, to ensure no one else is at risk.”
She added: "If there's a misdiagnosis in relation to one case, the question has to be asked are there other inaccuracies as well."
- Digital Desk