The indolent non-Hodgkin lymphomas (NHLs) represent approximately one-third of all malignant lymphomas (1,2); most are of B-cell lineage. Follicular lymphoma (FL) is the most common indolent lymphoma. Other indolent B-cell lymphomas include small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL), the marginal zone B-cell lymphomas (MZLs; extranodal, nodal, and splenic), and lymphoplasmacytic lymphoma (LPL), most cases of which are more specifically classified as Waldenström macroglobulinemia (WM) (Table 7-1) (2). Mantle cell lymphoma can morphologically resemble indolent B-cell lymphomas, but it is often clinically more aggressive and therefore is not covered in this chapter. Indolent T-cell NHLs, such as mycosis fungoides, are also not covered in this chapter.
Table 7–1Indolent Lymphomas |Favorite Table|Download (.pdf) Table 7–1 Indolent Lymphomas
|Entities included || |
Small lymphocytic lymphoma/chronic lymphocytic leukemia
Extranodal marginal zone B-cell lymphoma (MALT lymphoma)
Splenic B-cell marginal zone lymphoma
Nodal marginal zone lymphoma
Lymphoplasmacytic lymphoma (including Waldenström macroglobulinemia)
|Age ||Mostly a disease of older adults (usually over the age of 40 years) |
|Extent of disease ||Often disseminated (except MALT lymphoma), with >80% having stage III-IV disease. Bone marrow involvement common |
|Natural history ||Low proliferation fraction. Slow-growing; may have a waxing and waning course. Patients typically survive for many years. Transformation to large cell lymphoma can occur. |
|Curability ||Although current therapy such as radiotherapy or chemotherapy can often control the disease, it usually fails to eradicate the tumor except for early-stage disease (including MALT lymphoma). This is reflected in a continuous downward slope of relapse-free survival curves for patients with these lymphomas. |
Follicular lymphomas, the second most commonly occurring lymphoma in the United States, represents 22% of all NHLs (1) and 80% of indolent B-cell lymphomas. Follicular lymphoma occurs almost exclusively in adults, with an equal frequency in men and women. The incidence rates are highest among Caucasians, and median age at diagnosis is approximately 58 years (3). Risk of FL has been shown to be increased in persons with a first-degree relative with NHL or who worked as spray painters and among women with Sjögren syndrome (3). Of FL cases, 2% to 3% transform annually to diffuse large B-cell lymphoma (DLBCL) (4). Survival for patients with FL is improving, with a median survival of 8 to 10 years in the prerituximab era (2,5,6); in more modern eras, median survival has been reported to be greater than 18 years (7).
Patients with FL most often present with asymptomatic lymphadenopathy. Constitutional symptoms such as fever, drenching night sweats, and significant weight loss occur in approximately 15% of patients. Patients may have symptoms related to lymph node enlargement, especially when there are bulky masses in the retroperitoneum. Other symptoms ...