Lenalidomide and Rituximab in Treating Patients With Previously Untreated Stage II, Stage III, or Stage IV Follicular Non-Hodgkin Lymphoma

Inclusion Criteria: * Previously untreated, histologically confirmed follicular lymphoma, World Health Organization (WHO) classification grade 1, 2, or 3a (\> 15 centroblasts per high power field with centrocytes present) that is stage III, IV, or bulky (i.e., single mass \>= 7 cm in any uni-dimensional measurement) stage II * Bone marrow biopsies as the sole means of diagnosis are not acceptable, but they may be submitted in conjunction with nodal biopsies; fine needle aspirates are not acceptable for diagnosis * Failure to submit pathology specimens within 60 days of patient registration will be considered a major protocol violation * Institutional flow cytometry or immunohistochemistry must confirm CD20 antigen expression * Low or intermediate risk by Follicular Lymphoma International Prognostic Index (FLIPI): 0-2 risk factors * No prior systemic therapy for NHL, including chemotherapy or immunotherapy (e.g., monoclonal antibody-based therapy); patients may have received involved-field radiation therapy * No corticosteroids within two weeks prior to study entry, except for maintenance therapy for a non-malignant disease * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 * Measurable disease must be present either on physical examination or imaging studies; non-measurable disease alone is not acceptable; any tumor mass \> 1 cm is acceptable * Lesions that are considered non-measurable include the following: * Bone lesions (lesions if present …