Inclusion Criteria:

- Patients ≥ 18 years of age (at the time of signing the informed consent).

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

- Histologically confirmed mycosis fungoides or Sezary syndrome

- Stage IB to IVB disease at screening (TNMB classification, see Protocol Attachment C)

- Refractory disease after at least 2 prior therapies, which may include topicals,
phototherapy, bexarotene, interferon, and/or photopheresis. Patients may be
currently taking these medication and therapies may be used in combination.

- Determined to have adequate baseline organ function defined as:

Hepatic: Total bilirubin ≤ 1.5 x upper limit of normal (ULN),AST and ALT ≤ 3.0 x ULN

- Hematologic: Platelets ≥ 75 x 109/L

- Absolute neutrophil count (ANC) ≥ 1.0 x 109/L,Hemoglobin ≥ 8.0 mg/dL

- Renal: Creatinine clearance ≥ 30 ml/min (Appendix; Cockcroft-Gault formula)

- At least 3 months since the initiation of any new CTCL treatments.

- Stable or progressive disease despite current treatment regimen over the last 3
months.

- All study participants must be registered into the mandatory RevAssist® program,
and be willing and able to comply with the requirements of RevAssist®.

- 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 prior to prescribing lenalidomide
(prescriptions must be filled within 7 days) 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.

- A female of childbearing potential is a sexually mature woman who:

1. has not undergone a hysterectomy or bilateral oophorectomy

2. has not been naturally postmenopausal for at least 24 consecutive months
(has had menses at any time in the preceding 24 consecutive months). See
Appendix: Risks of Fetal Exposure, Pregnancy Testing Guidelines and
Acceptable Birth Control Methods.

- Disease free of prior malignancies for ≥ 5 years, with exception of basal cell
and squamous cell carcinoma of the skin, or breast or cervix in situ carcinoma.

- Expected survival of > 6 months.

- Able to take aspirin (81 or 325 mg) daily as prophylactic anticoagulation.
Patients intolerant to aspirin may use warfarin or low molecular weight heparin.

Exclusion Criteria:

- Any serious medical condition, laboratory abnormality, or psychiatric illness that
would prevent the subject from signing the informed consent form.

- Female subjects who are pregnant, nursing, or planning pregnancy. Female subjects not
using at least 2 forms of birth control during the trial, unless the subject is
considered sterile (history of hysterectomy or postmenopausal with no menses for the
last 24 consecutive months).

- History of deep venous thrombus (DVT) or pulmonary embolism (PE), unless currently on
anticoagulation therapy (warfarin or heparin).

- Subjects receiving chemotherapeutic agents (or have received in the last 3 months),
vorinostat, or methotrexate.

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

- Known hypersensitivity to thalidomide.

- History of erythema nodosum or desquamating rash while taking thalidomide or similar
drugs.

- Any prior use of lenalidomide.

- Known seropositive for or active viral infection with human immunodeficiency virus
(HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV). Patients who are
seropositive because of hepatitis B virus vaccine are eligible..

- Having a serious concomitant systemic disorder that could preclude the patient from
benefiting or completing the study based on discretion of the investigator.

- Any condition or circumstance judged by the investigator that would render the
clinical trial detrimental or otherwise unsuitable for the patient's participation.

- Neuropathy > grade 2