A man who complained to doctors of severe chest pains was stunned when told his suspected tumour was actually a fir tree growing inside his lung.

Artyom Sidorkin, 28, from the Urals region of Russia, is believed to have inhaled a seed which then sprouted inside him.

Doctors were convinced he had cancer after he came to them complaining of agonising chest pains and coughing up blood.

An X-ray showed what was believed to be a tumour, and he was rushed to the operating theatre.

"We were 100% sure," said surgeon Vladimir Kamashev from Izhevsk in the Urals.

"We did X-rays and found what looked exactly like a tumour. I had seen hundreds before, so we decided on surgery."

Before removing the major part of the man's lung, the surgeon investigated the tissue taken in a biopsy.

"I thought I was hallucinating," said Dr Kamashev.

"I asked my assistant to have a look: 'Come and see this - we've got a fir tree here'."

"He nodded in shock. I blinked three times as I was sure I was seeing things."

The 2in (5cm) spruce, which was said to be touching the man's capillaries and causing severe pain, was removed.

Mr Sidorkin, now recovering after the op, said: "To be honest I did not feel any foreign object inside me. But I'm just so relieved it's not cancer."