This two-picture combo handout file photos provided by Peter Kahn, the attorney of imprisoned American Alan Gross, shows Gross in 2009 and in 2012. (Uncredited/AP)

An American imprisoned in Cuba for nearly three years is in poor health and may not survive to serve out the remainder of his 15-year sentence, his wife said Tuesday after visiting him last week.

Alan Gross has lost 105 pounds and has a growth on his back that no American doctor has been allowed to inspect, according to his wife, Judy Gross, and an attorney for the family.

“He looks like a concentration camp victim,” Judy Gross said in a brief interview, adding in a statement that she fears he won’t survive.

Gross said in the interview that her husband, a former U.S. government contractor, is angry with the Cuban and American governments.

“He feels like he’s been dropped and ignored” by the United States, she said. “The government sent him there, and he feels like they left him there.”

Gross saw her husband daily during a five-day trip to Cuba that ended Sunday. This was her first visit in more than six months, and his health deteriorated sharply in that time, said Jared Genser, the family’s attorney.

Alan Gross, 63, was overweight at the time of his arrest, but he is now dangerously thin and his health is failing, Genser said. Cuban doctors have said the mass on his back is not life-threatening, but the lawyer said Gross wants an independent diagnosis.

Gross, of Potomac, has been behind bars since December 2009, when he was arrested in Cuba for distributing computer equipment that could be used for Internet access. At the time, he was working under a contract with the U.S. Agency for International Development.

The Cuban government says Gross was part of a multimillion-dollar U.S. effort to undermine it. He says he was trying to improve communication services for Cuba’s small Jewish community.

Gross initially identified himself as a representative of a Jewish humanitarian organization but later acknowledged his U.S. government connection.

He was sentenced to 15 years in prison and has run out of appeals. Although he maintains his innocence, his lawyer is appealing to the Cuban government to release him on humanitarian grounds.

Judy Gross begged Cuban President Raul Castro to “put an end to our anguish and let Alan come home.”

There was no immediate reaction from the Cuban government.

The State Department has regularly called on Cuba to release Gross. “We share Judy Gross’s frustration with her husband’s unjust detention by Cuban authorities,” said Roberta Jacobson, the assistant secretary for Western Hemisphere affairs. “The administration has and will continue to work through all appropriate diplomatic means to urge Alan Gross’s immediate release.”