Twenty years after he swallowed a pen cap in primary school, a Chinese man finally had the object removed from his lung, Central European News (CEN) reported.

Doctors initially thought Lei Hou, 32, had a tumor after he’d been complaining of constant coughing. During surgery, they found a plastic pen top stuck in his bronchial passageway.

"I am pleased that my health problem has finally been sorted out. At least I can breathe properly now,” Lei told CEN.

Lei, who lives in the Zhejiang Province in East China, recalled he had accidentally swallowed the object in primary school while he was doing homework. His only symptom had been occasional difficulty breathing, so he never went to a doctor.

The pen cap prevented air from entering the lung, causing it to shrink, and it will never work again, doctors told Lei. They warned him that a lung starts to lose function after a week with no oxygen and completely after two years. If Lei had gone for a check-up, it could have been avoided, they said.

"The patient is now in recovery. It is a shame he did not report his symptoms a lot earlier than he did. If he had come to us earlier we might have been able to save his lung,” a hospital spokesman told CEN.