A 73-year-old woman was diagnosed with ovarian cancer after a bizarre red lump grew out of her belly button.
The woman - who has not been named - went to hospital when the 'umbilical nodule' became painful and grew to 2cm across over four months.
Scans later revealed she was also suffering from a 11x11cm tumour in her pelvis, which had spread to her belly button.
The red lump - known as a Sister Mary Joseph’s nodule - can occur with ovarian cancer but is 'relatively rare', doctors said.
The patient, from Spain, is said to have made a full recovery after undergoing chemotherapy and surgery to remove the mass.
The woman went to A&E two days after the lump in her belly button started bleeding.
She was treated by Dr Javier Barambio, a general surgery and digestive system physician at the Hospital Universitario Fundacion Jimenez Diaz in Madrid.
Upon examination, the nodule was painful and firm to touch, doctors wrote in a case report in The New England Journal of Medicine.
Scans revealed the pelvic mass - which was 9.5cm deep - as well as fluid in her abdomen and cancerous cells in her peritoneum.
The peritoneum is a thin layer of tissue that lines the inside of the abdomen and its organs, such as the liver.
Biopsies of both the Sister Mary Joseph’s nodule and the pelvic mass confirmed the patient had ovarian cancer.
Dr Barambio told Live Science she is now free of the disease and in good health.
A Sister Mary Joseph’s nodule protrudes from the belly button and can be a sign of severe or metastatic cancer, according to Stanford Medicine.
It is most likely to occur with gastrointestinal - such as bowel or pancreatic - or gynaecological - like ovarian and uterine - forms of the disease.
The nodule's cause is unclear but is thought to be due to cancerous cells spreading to the belly button either via the peritoneum, lymph system or circulation.
It is also unknown how common the lump is, with it generally being a sign of advanced cancer with a poor prognosis.
The nodule is named after the US nurse Sister Mary Joseph, who first drew attention to it in 1929.
Source: The Daily Mail