After 25 years swimming about in stomach acid, a fully-functioning pen has been removed by surgeons at the Royal Devon and Exeter Hospital Foundation Trust, reports the British Medical Journal.
Doctors Tarek Shirazi, Oliver Richard Waters and Tawfique Daneshmend gave their report to the journal after performing a CAT scan on a 76-year-old female pensioner from the local area who had been complaining of bowel troubles.
As it turned out, the felt-tip pen that had been living in her alimentary canal wasn't what caused her pain - that was a simple case of severe diverticulitis, which many older people suffer from - it was just sheer chance that the doctors spotted the pen during the scan.
Previous x-rays hadn't shown anything unusual, so her GP and husband dismissed her story of accidentally swallowing a pen during an attempted home tonsil examination back in 1986.
"This case highlights that plain abdominal x-rays may not identify ingested plastic objects and occasionally it may be worth believing the patient’s account however unlikely it may be," says the BMJ journal.
A quick piece of ear, nose and throat surgery later and the pen was swiftly removed - even though it wasn't actually hurting the patient in any way.
The doctors tested the pen once the surgery was over, writing the word "HELLO" on a piece of paper with no trouble at all.
It goes to show - no point throwing old pens away... they may well still work. Even if they've been inside you for a quarter of a century...