New Jersey ? Sen. Frank Lautenberg, at 86 the nation’s second-oldest U.S. senator, has curable lymphoma of the stomach, his office said Friday.

Doctors for the Democrat found B-cell lymphoma that will require treatment over the next few months, spokesman Caley Gray said in a news release. He will not be resigning, Gray said.

Independent doctors agree that Lautenberg’s type of lymphoma is usually treatable.