After suffering an erection for an entire week, a 52-year-old man had to undergo surgery to have one-half of his penis removed.
The man, who remains unnamed, said the erection first appeared randomly and that he was not sexually stimulated at the time, according to the Daily Mail.
Although he wasn't too worried at first, the man decided to see a medical professional a week later, when his penis was in so much pain he said it felt as though it was "about to explode."
An erection that lasts more than four hours is considered a medical emergency.
Doctors said the persistent erection was a result of bladder cancer. Cancerous tumors were obstructing blood vessels in the penis, causing the erection.
The man was previously told he had early stages of cancer three years ago and was advised to have his bladder removed.
"The patient refused because he didn't want to wear a urine bag for the rest of his life," said the man's doctor, Wang Hung-jen.
Without treatment, the cancer spread and medical experts decided they had no choice but to amputate part of the man's penis.
Surgeons cut into both the penis and the bladder to alleviate some of the pain.
The surgery was considered a success and the man will start chemotherapy as soon as he fully recovers from the procedure.
Long-lasting erections, a condition known as priapism, are usually caused by drugs taken to treat erectile dysfunction or by blood disorders like, sickle cell disease, according to Britain's National Health Service.
To treat priapism, doctors will usually inject the penis with a drug to narrow the blood vessels to the penis to relieve swelling. The faster a man receives treatment, the more likely he will able to regain normal function of his penis.
If the condition is not treated within 24 hours, the penis is likely to be permanently damaged and it will be difficult to maintain erections in the future.
Because this patient waited so long, doctors had no choice but to operate. Surgery is considered to be the last option to treat priapism and is only used when all other options have been exhausted.
The man, who is based in Taiwan, may not be able to have sex again, according to The Sun.
"He isn't married and didn't request an evaluation of potential sexual function," said his doctor.
"Right now the priority is to save his life."