A man from the U.S. has incidentally discovered a cancerous tumour on his kidney because of an injury from a potential shark attack that pushed him to visit the hospital. Doctors said that the shark encounter opened the chance for the healthy 39-year-old man to remove the tumour, which may grow over the years.

Eugene Finney, from Fitchburg in Massachusetts, was in a beach in California with his family. Finney was with his 10-year-old daughter in the water about 10- to 15-feet deep when a large wave forced him to dive under with his daughter.

As he tried to go to the surface, Finney said that a large object hit his back. "I was hit in the back hard. Really hard. I've never been hit that hard in my life," he said.

Finney was forced to swim back to the shore with his daughter, and he found that his back was bleeding. A foot-long gash on his upper back had caused the bleeding. His girlfriend and son, who stayed on the shore, claimed that they saw fins in the area where he had been swimming, Finney told the CNN.

Finney returned to Massachusetts few days after the incident for his work at the Fitchburg Art Museum. However, chest pain and sleeping problems led him to visit the hospital.

Finney went through an EKG and chest X-rays. The results show that he had been suffering inflammation on his heart because of the interior bruising of the thoracic cavity caused by the blunt force trauma he experienced in California. The doctors then had an "incidental discovery" while observing his injury. A walnut-sized tumour was discovered on his right kidney - that could be cancerous - which surprised Finney.

"I was thinking 'You have to be kidding me'... I couldn't really believe it," he said.

In September, Finney underwent a surgery to remove the tumour, including 20 percent of his right kidney. The tumour was then proven cancerous based on the biopsy reports.

"If he didn't have the encounter with the shark, and given the fact that he's a healthy 39-year-old man, the tumour probably would have grown over the next five, six years,” said Dr Ingolf Tuerk, director of the robotic-assisted surgery programme at St. Elizabeth's Medical Centre, who removed the tumour in Finney’s kidney. “The surgery could have been significantly less successful had the tumour not been located early," he added.

To date, Finney is still recovering, but it is still not clear what caused the injury on his back. According to Lt Claude Panis, of the Huntington Beach Marine Safety Division, in California, there could be other objects that could have injured Finney, such as stingrays, debris, another swimmer or a surfboard.

Two days after Finney’s experience on the beach, a juvenile great white shark has bumped a surfer in the same area. The new incident pushed the authorities to temporarily close the beach.

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