Durbin's office said surgeons removed the small tumor on Thursday. Spokesman Joe Shoemaker said a preliminary biopsy showed no signs of cancer, although these kinds of tumors can be malignant.
A statement from Durbin's office said further treatment is not expected. It said the preliminary biopsy results "demonstrate a favorable prognosis" and Durbin should be able to resume a full schedule as early as next week.
Durbin, 65, is second to Majority Leader Harry Reid in the Senate Democratic leadership ranks.