They found the growth was a benign tumour made up of fat cells, known as a lipoma.
Co-author of the report, Dr Tunde Abdulsalam, who practices in Dublin, told MailOnline this was one of the biggest lipomas he had ever seen.
He said: "It is unusual to let it grow that big. Most patients would have it removed sooner for cosmetic reasons.
"From my clinical experience most lipomas are small in size. And most patients frequently leave it alone because it is relatively stable for years and does not affect bodily function.
"But in some cases, it can increase in size as a person's BMI increases."
The increase in size can also indicate the tumour is cancerous, hence why the doctors carried out an MRI and a biopsy immediately to rule this out, he added.
The woman is now on the waiting list to have the growth removed with surgery, where it will be weighed.
Lipomas can occur on any part of the body but frequently occur on the torso and the arms.
They usually occur in people aged 40 to 60 years old and tend to be painless, soft and small.
Size-wise, they are generally around 1cm, but can grow to more than 10cm in size.
Usual treatment is surgery or liposuction.
The news comes after MailOnline reported on the case of a 13-year-old girl had a rugby ball-sized tumour removed from her breast in May this year.
The teenager had concealed the huge growth for eight months.
She opted to have the mass removed surgically.
During the procedure, two tumours with a total weight of 2.7kg were removed, and doctors managed to preserve her breast tissue.
- Daily Mail
