Inclusion Criteria:

1. Understand and voluntarily sign an Informed Consent form

2. Age > 18 years at time of signing the Informed Consent Form

3. Able to adhere to the study visit schedule and other protocol requirements.

4. Patients with histological confirmation of diffuse large B cell lymphoma with at
least one of the following characteristics:

- High or intermediate IPI score (See Appendix 8.0 for IPI scoring criteria)

- Patients who are still PET scan positive mid therapy with R-CHOP, but, have
turned negative after completion of therapy.

- Low risk International prognostic index ie., an IPI score of <3 if age >60 years
or <2 if age is less than or equal to 60 with c-myc positive by Fluorescent In
situ Hybridization.

5. No other previous lymphoma therapy, hormonal therapy or surgery, except for standard
therapy with R-CHOP with or without radiation and with or without prophylactic
Methotrexate therapy. Patients must be enrolled within 4-12 weeks of completion of
therapy.

6. At the time of study entry following standard therapy with R-CHOP±RT, patients should
be in complete remission.

7. ECOG performance status of ≤ 2 at study entry

8. Laboratory test results within these ranges:

- Absolute neutrophil count ≥ 1500/mm³

- Platelet count ≥100K /mm³

- Serum creatinine ≤ 2.0 mg/dL

- Total bilirubin ≤ 1.5 mg/dL

- AST (SGOT) and ALT (SGPT) ≤ 2 x ULN

9. Disease free of prior malignancies for ≥ 3 years with exception of currently treated
basal cell or squamous cell carcinoma of the skin, or carcinoma "in situ" of the
cervix or breast.

10. Females of childbearing potential (FCBP)† must have a negative serum or urine
pregnancy test with a sensitivity of at least 50 mIU/mL within 10 - 14 days prior to
and again within 24 hours of starting lenalidomide and must either commit to
continued abstinence from heterosexual intercourse or begin TWO acceptable methods of
birth control, one highly effective method and one additional effective method AT THE
SAME TIME, at least 28 days before she starts taking lenalidomide. FCBP must also
agree to ongoing pregnancy testing. Men must agree to use a latex condom during
sexual contact with a FCBP even if they have had a successful vasectomy. All patients
must be counseled at a minimum of every 28 days about pregnancy precautions and risks
of fetal exposure -A female of childbearing potential is a sexually mature woman who:
1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been
naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at
any time in the preceding 24 consecutive months).

Exclusion Criteria:

1. Any serious medical condition, laboratory abnormality, or psychiatric illness that
would prevent the subject from signing the Informed Consent

2. Pregnant or breast feeding females. (Lactating females must agree not to breast feed
while taking lenalidomide).

3. Any condition, including the presence of laboratory abnormalities, which places the
subject at unacceptable risk if he/she were to participate in the study or confounds
the ability to interpret data from the study.

4. Use of any other experimental drug or therapy within 28 days of baseline.

5. Known hypersensitivity to thalidomide.

6. The development of erythema nodosum if characterized by a desquamating rash while
taking thalidomide or similar drugs.

7. Any prior use of lenalidomide.

8. Concurrent use of other anti-cancer agents or treatments.

9. Known positive for HIV or infectious hepatitis, type B or C.

10. A diagnosis of deep vein thromboses in the preceding 3 months of study enrollment.