Follicular small-cleaved cell lymphoma and follicular mixed small-cleaved and large cell lymphoma do not have reproducibly different disease-free survival or OS.
Therapeutic options include watchful waiting; rituximab, an anti-CD20 monoclonal antibody, alone or with purine nucleoside analogs; oral alkylating agents; and combination chemotherapy. Radiolabeled monoclonal antibodies, vaccines, and autologous or allogeneic bone marrow or peripheral stem cell transplantation are also under clinical evaluation. Currently, no randomized trials guide clinicians about the initial choice of rituximab, nucleoside analogs, alkylating agents, combination chemotherapy, radiolabeled monoclonal antibodies, or combinations of these options. On a comparative basis, it is difficult to prove benefit when relapsing disease is followed with watchful waiting, or when the median survival is more than 10 years. Follicular lymphoma in situ and primary follicular lymphoma of the duodenum are particularly indolent variants that rarely progress and rarely require therapy.[17,18]
Patients with indolent lymphoma may experience a relapse with a more aggressive histology. If the clinical pattern of relapse suggests that the disease is behaving in a more aggressive manner, a biopsy should be performed. Documentation of conversion to a more aggressive histology requires an appropriate change to a therapy applicable to that histologic type. Rapid growth or discordant growth between various disease sites may indicate a histologic conversion. The risk of histologic transformation was 30% by 10 years in a retrospective review of 325 patients from diagnosis between 1972 and 1999. In this series, high-risk factors for subsequent histologic transformation were advanced stage, high-risk FLIPI, and expectant management. The median survival after transformation was 1 to 2 years, with 25% of patients alive at 5 years and with approximately 10% to 20% of patients alive 10 years after re-treatment. (Refer to the Treatment for Aggressive, Recurrent Adult NHL section of this summary for a description of the regimens used to treat histologic conversions.) The durability of the second remission may be short, and clinical trials should be considered.[21,22,23]
Lymphoplasmacytic Lymphoma (Waldenström Macroglobulinemia)
Lymphoplasmacytic lymphoma is usually associated with a monoclonal serum paraprotein of immunoglobulin M (IgM) type (Waldenström macroglobulinemia).[24,25,26] Most patients have bone marrow, lymph node, and splenic involvement, and some patients may develop hyperviscosity syndrome. Other lymphomas may also be associated with serum paraproteins.