The fossilized rib of a Neanderthal carries evidence of the oldest bone tumor ever recorded, according to research published today in PLoS One.

It is a serendipitous discovery given the rarity of Neanderthal fossils. It is also surprising because this class of cancer is strongly connected to the recent expansion in human lifespan, and Neanderthals only lived for about half as long as today's humans.

"This was a young adult Neanderthal," said lead author Dr. David Frayer, a biological anthropologist at the University of Kansas. The bone cancer specimen was collected at the turn of the 20th century in the Krapina rock shelter, located some 34 miles north of what is now known as Zagreb, Croatia.

"Krapina has yielded one of the largest samples of human skeletal remains accumulated from any Upper Pleistocene site," wrote the authors. Over 900 human bones were uncovered during the excavation that took place between 1899 and 1905. Radiometric and tooth enamel dating suggests bones from this site are between 120,000 to 130,000 years old.

Prior to this finding, the earliest known bone cancers were discovered in mummies from Ancient Egypt and date back between 1,000 and 4,000 years.

The tumor found in this study blows that figure away, predating the Egyptian specimens by over 100,000 years.

X-ray scans suggest the bone lesion is a 'fibrous dysplasia', a type of benign tumor that is the most common cancer found in ribs today. It is a developmental disorder marked by soft fibrous tissue replacing the normal core of the bone. This soft tissue expands, which weakens the bone and can cause fracture. The researchers ruled out other conditions that may have been at fault like bone infection or a cartilage cyst from bone marrow.

"The diagnosis was made by an experienced radiologist, co-author Dr. Morrie Kricun, who has identified hundreds of these in living people at the University of Pennsylvania hospital," continued Frayer. "Along with him, we eliminated all other possibilities."

This is not the oldest remnant of cancer ever discovered, however, as a 350 million-year-old tumor was found in a fish fossil from Cleveland, Ohio.

Source: Monge J, Kricun M, Radovcic J, Radovcic D, Mann A, Frayer DW. Fibrous Dysplasia in a 120,000+ Year Old Neandertal from Krapina, Croatia. PLoS One. 2013.