The risk of late relapse is higher in patients who manifest both indolent and aggressive histologies. While indolent NHL is responsive to immunotherapy, radiation therapy, and chemotherapy, a continuous rate of relapse is usually seen in advanced stages.Patients, however, can often be re-treated with considerable success as long as the disease histology remains low grade.Of patients with aggressive NHL, more than 50% can be cured.
Knowledge of cell surface markers and immunoglobulin and T-cell receptor gene rearrangements may help with diagnostic and therapeutic decisions.
The clonal excess of light-chain immunoglobulin may differentiate malignant from reactive cells.
Gene expression profiles of tumor biopsy specimens suggest that follicular lymphoma that is surrounded by infiltrating T-lymphocytes has a much longer median survival (13.6 years) than follicular lymphoma that is surrounded by dendritic and monocytic cells (3.9 years) ( 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.[15,16] Currently, no randomized trials have mature results to 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.
As a result, the Working Formulation has become outdated and less useful to clinicians and pathologists.
Thus, European and American pathologists have proposed a new classification, the Revised European American Lymphoma (REAL) classification.[5-8] Since 1995, members of the European and American Hematopathology societies have been collaborating on a new World Health Organization (WHO) classification, which represents an updated version of the REAL system.[9,10] The WHO modification of the REAL classification recognizes three major categories of lymphoid malignancies based on morphology and cell lineage: B-cell neoplasms, T-cell/natural killer (NK)-cell neoplasms, and Hodgkin lymphoma (HL).Since the prognosis and the approach to treatment are influenced by histopathology, outside biopsy specimens should be carefully reviewed by a hematopathologist who is experienced in diagnosing lymphomas.Although lymph node biopsies are recommended whenever possible, sometimes immunophenotypic data are sufficient to allow diagnosis of lymphoma when fine-needle aspiration cytology is preferred.[1,2] Historically, uniform treatment of patients with non-Hodgkin lymphoma (NHL) has been hampered by the lack of a uniform classification system.In 1982, results of a consensus study were published as the Working Formulation. The Working Formulation combined results from six major classification systems into one classification.This allowed comparison of studies from different institutions and countries.Indolent NHL types have a relatively good prognosis with a median survival as long as 20 years, but they usually are not curable in advanced clinical stages. Early-stage (stage I and stage II) indolent NHL can be effectively treated with radiation therapy alone.