An American man who had never been to Ireland began speaking in an Irish accent after developing a rare form of cancer, according to a study published by BMJ in January.

The man, who was being treated for a form of prostate cancer, presented with an uncontrollable ‘Irish brogue’ accent despite no Irish background, consistent with foreign accent syndrome (FAS). 

The team who studied the man's case wrote: "His accent was uncontrollable, present in all settings and gradually became persistent."

The authors of the study believed his foreign accent syndrome was caused by paraneoplastic neurological disorder (PND), which is caused when cancers outside of the brain trigger an immune response that can impact the nervous system from afar.

"This unusual presentation highlights the importance of additional literature on FAS and PNDs associated with prostate cancer to improve understanding of the links between these rare syndromes and clinical trajectory," wrote the authors of the case study.

The man eventually died in palliative care, with the team noting "his Irish brogue-like accent was maintained until his death.”

Dr. Andrew Armstrong, a professor at Duke University who co-wrote the report, told Newsweek: "We don't have a 'smoking gun' explanation in this case.

"Other possibilities are psychological, although he did not have major issues with anxiety or depression and actually was fairly amused by this FAS development."

According to Sunday World, the man had never been to Ireland or previously spoken in an Irish accent, although he did have Irish family and friends and had lived in England briefly in his 20s.

The disorder is extremely rare, with only around 100 people in the world having been diagnosed with the condition.

FAS usually follows a traumatic head injury or stroke. There are only two other reports of malignant cancers triggering the disorder, with this being the first case linked specifically to prostate cancer.

Two years ago, 60 Minutes Australia reported on the cases of two Australian women who developed "Irish accents" due to FAS. Neither woman had ever been to Ireland.

Angie Yen 28, woke up with an Irish brogue a week after undergoing tonsil surgery, while Kate Baggs, 30, began speaking with an Irish accent after suffering from a hemiplegic migraine in 2019.