Both strategies have been shown to increase survival rates since 2003 [24,25]. bendamustine are the most relevant. Regrettably, these clinical tests have included only individuals with symptomatic FL. The results of a recently reported medical trial display that treatment with single-agent rituximab prolongs progression-free survival rates, time to fresh treatment and the quality of existence of asymptomatic individuals, as compared with the active surveillance strategy. Longer follow-up of these results and data concerning overall survival are awaited before this treatment can be recommended as the standard initial therapy. Summary There are different therapeutic options for asymptomatic FL individuals, but no data are currently available to show which option is the best. Individuals need to understand the risks and benefits of observation versus treatment before a final decision can be made. For patients who want active treatment the administration of four weekly rituximab doses should be considered. Background Follicular lymphoma (FL) is the second most common subtype of lymphoma in Western Europe, as it represents 22-25% of non-Hodgkins lymphomas (NHL), according to the WHO histological classification [1,2]. The annual incidence of FL improved from two to three per 100,000 individuals/year during the 1950s to five to seven per 100,000 individuals/year in 2009 2009, having a prevalence of 40 instances per 100,000 people . FL originates in follicular-centre B cells, usually in the lymph nodes, and maintains the phenotypic characteristics and gene manifestation of these cells. Approximately 85% of FL individuals present with chromosomal translocation t(14;18), which leads to overexpression of the BCL-2 oncogene and results in resistance to apoptosis. 4-Azido-L-phenylalanine t(14,18) is not specific for FL, as it is present in 30% of diffuse large B-cell lymphomas (DLBCL) and even in some healthy individuals . Morphologically, FL is composed of small B-cells (centrocytes) and 4-Azido-L-phenylalanine large B-cells (centroblasts) that are clonally related. The morphological distribution follows a nodal growth pattern similar to that of the germinal centres observed in secondary lymphoid follicles. Neoplastic follicles may be common in tumoural cells; the rest of the tumour exhibits a diffuse growth pattern . FL is definitely classified into three marks according to the quantity of centroblasts present in the tumour cells (Table ?(Table1).1). In marks 1 and 2, centrocytes prevail; in grade 3 large cells are more numerous. Grade 3 is divided into 3A (when centrocytes are still present) and 3B (characterised by the presence of solid bedding of centroblasts). Although grade 3B FL has a worse prognosis and its natural history and treatment are similar to those of DLBCL, the genetic characteristics and medical behaviour suggest that grade 3A FL exhibits indolent behaviour very similar to that of grade 1-2 FL . Table 1 Follicular lymphoma grading according to the WHO classification1 thead valign=”top” th align=”remaining” rowspan=”1″ colspan=”1″ Grading Definition /th ? /thead em Grade 1C2 (low grade) 0C15 centroblasts per hpf* /em hr / ? 1 0C5 centroblasts per hpf hr / ? 2 6C15 centroblasts per hpf hr / ? em Grade 4-Azido-L-phenylalanine 3 15 centroblasts per hpf /em hr / ? 3A: centrocytes present hr / ? 3B: solid bedding of centroblasts hr / ?Follicular Pattern hr / ? Follicular 75% hr Rabbit Polyclonal to MNK1 (phospho-Thr255) / ? Follicular and diffuse 25C75% hr / ? Focally follicular 25% hr / ? Diffuse 0%**? Open in a separate windowpane * hpf?=?high-power field of 0.159?mm2. ** Diffuse areas comprising 15 centroblasts per hpf are reported as DLBCL with FL (marks 1 to 2 2, 3A or 3B). Note that in small biopsies the absence of follicles may reflect a sampling error. FL is the most common indolent lymphoma accounting for 70% of all indolent lymphomas..