A tumor weighing 28 kilogram was surgically removed by German doctors from a 60-year-old woman.
A spokesman from the university clinic in the eastern city of Dresden said the woman, Irmtraud Eichler, had made a full recovery after the seven-hour operation and was now able to walk again with crutches.
The so-called "borderline" tumour, measuring 60 centimetres (24 inches) by 50 centimetres, attached itself to an ovary and Eichler began to put on weight at an alarming rate.
Her doctor put the weight gain down to a combination of diabetes and a lack of activity and prescribed a course of anti-obesity medicine.
However, when she could barely stand due to the swelling, her daughter insisted on a second opinion and an ultrasound scan revealed the growing tumour, which was found to be neither benign but not especially malignant either.
The operation removed not only the tumour, but also her uterus, ovaries and thyroid, which had expanded, causing her windpipe to contract and have breathing difficulties.
When removed, the tumour filled a wheelbarrow, the spokesman said.
Eichler lost a total of 40 kilogrammes during the operation and described herself as "super happy."
"I cannot thank the doctors enough. I am a new person," she said according to local news agency DPA.