According to Komsomolskaya Pravda, this fir sapling was removed from a patient's lung. Skeptics are unimpressed. (CBC)

A man who was coughing up blood and complaining of chest pain seems to have had a five-centimetre fir tree in his lungs — unless, of course, it was all a hoax.

Artyom Sidorkin, 28, was treated at a hospital in Izhevsk, Russia, last week, the Komsomolskaya Pravda newspaper reported.

When doctors X-rayed his chest, they found signs of a tumour, so they operated to take a biopsy. That's when they found what appeared to be a fir sapling, it's claimed.

Dr. Vladimir Kamashev, deputy head surgeon at the Udmurtian Cancer Centre, told the newspaper that he blinked three times on seeing the green needles and called an assistant to take a look.

The branch was too large to have been inhaled or swallowed, the doctors said.

Rather, they think Sidorkin may have inhaled a small bud that sprouted inside him.

Too dark to sprout

But commenters have questioned whether it could grow from a seed.

"It looks like a hoax to me," said Prof. Peter Kotanen, a plant ecology researcher at the University of Toronto at Mississauga.

"It's dark inside a lung, and most seeds need light to stimulate germination and to grow."

Asked to looked at internet photos of the purported seedling in lung tissue, Kotanen said firs have small seeds, while the seedling illustrated is quite big.

"I don't see how it could get anywhere near that size without photosynthesis," Kotanen said in an email to CBC News.

"Finally, it looks pretty healthy, which I wouldn't expect. Most plants that grow in the dark lack chlorophyll, and are very yellow and unhappy looking."

Also, human body temperatures would not be amenable to the development of a cold-adapted tree species, said Prof. Sean Thomas, Canada research chair in forests and environmental change at the University of Toronto.

X-ray discrepencies

The X-ray also depicts a conifer with different leaf angles and a more filamentous appearance than the shoot in the lung tissue, Thomas said.

Assuming that the whole thing is not a complete hoax, it's more likely that a fir shoot was inhaled and lodged in the lung, or perhaps fell in during the operation, he said.

An X-ray accompanying the report also shows a growth plate in the shoulder that is not fused, which points to a pediatric case, not a 28-year-old patient, according to a radiologist consulted by CBC News.

The claim has not been independently verified, and the story ran on what would be April Fool's Day according to the Russian Julian calendar. Russian news agencies have been known to publish hoaxes in the past.