When a 44-year-old Scottish woman visited the doctor’s office with complaints of pain and loss of movement in her left arm and shoulder, doctors were perplexed. X-ray images showed a lesion in her humerus bone that would normally would be an indication of cancer, but biopsy results didn’t show cancer.
For more than a year the woman not only suffered from pain and swelling, but her arm bone would fracture from minor injuries. It wasn’t until 18 months later doctors made a surprising discovery: her bones were “vanishing”.
It's an extremely rare condition called Gorham-Stout disease (GSD) – or “vanishing bone disease” – where patients progressively lose bone mass. It's also a mystery to doctors who don't know its etiology or cure. Bone loss (osteolysis) and the overgrowth (proliferation) of lymphatic vessels progressively destroy the bone, causing it to be absorbed into the circulation of cells or tissues. Initially, “disappearing” bones might look as though they have patchy osteoporosis. Over time, deformities occur while bone mass is lost or shrinks, eventually leading to bones "vanishing" over time.
What causes this rare and poorly understood disease is a mystery in itself. According to a case study published in BMJ Case Reports, of the 64 reported cases, eight involved the humerus. The condition was first reported in 1838 after a young man’s humerus gradually vanished, and since then nearly all cases have involved people under the age of 40. Because of its rarity, GSD is difficult to diagnose and its prognosis is often unpredictable. While it is generally benign, it can lead to disabling impairment. Worse yet, there is no cure. Treatments include removing the bone through surgery, radiation to keep the disease from spreading, and taking bisphosphonates that prevent bone loss.
It can affect one or multiple bones at a time, including the arms, legs, collarbone, jaw, and pelvis. If it affects the spine or skull base, it could ultimately lead to paralysis. In cases where the rib cage is affected, a buildup of fluid between the membrane lining the lungs could prove fatal.
Oddly enough, in some cases, the disease spontaneously disappears as mysteriously as it first appeared.
As for the woman in Scotland, it's unclear whether she was treated for her "vanishing" bones or what her ultimate prognosis was. IFLScience reached out to researchers with the Royal Infirmary of Edinburgh in Scotland but did not receive a response at the time of publication.