When marginal zone lymphoma, splenic type occurs in association with hepatitis C (serologic positivity for hepatitis C antibody is sufficient proof) the lymphoma may regress completely when the hepatitis is effectively treated with interferon or interferon plus ribavirin (Hermine, N Engl J Med, 2002;347:89-94). All lymphoma patients, regardless of type, should have hepatitis C serology performed at diagnosis. Any patient found to have positive serology for Hepatitis C and a small B-cell lymphoma, especially marginal zone lymphoma, splenic type, should be considered for treatment with interferon and if that fails to suppress the hepatitis C, with the addition of ribavirin.