The classification of non-Hodgkin's lymphomas (NHL's) has been a mess for years. If you don't like current classification schemes, just wait a couple of years and a new one will be promulgated. The following table lists salient features of some of the most common types of NHL's in the REAL (revised European-American lymphoma) classification:

Non-Hodgkin's Lymphomas
TypeHistologic FeaturesImmunogeneticsClinical Features
Small Lymphocytic Lymphoma Small and well-differentiated B lymphocytes, with diffuse effacement of nodal architecture and no follicles CD19, 5; Bcl-2 and Bcl-6 expression Seen in older adults, it is essentially the solid tissue (lymph nodal) component of chronic lymphocytic leukemia; disease tends to be generalized but with indolent course and prolonged survival; some may transform to more aggressive lymphomas
Follicular Lymphoma (predominantly small cell) Nodal architecture is effaced by monotonous, crowded follicles composed of monomorphous small cleaved B-lymphocytes CD19, 20, 79a; t(14:18); Bcl-2 expression Most common type, seen in adults, often involves multiple lymph nodes, course is indolent, with prolonged survival, though some may transform to a large cell lymphoma
Diffuse Large B-cell Lymphoma Cells are large, with prominent nucleoli and abundant cytoplasm and many mitoses. Most are B-cell, but 20% are T-cell phenotype CD19, 20, 79a; some have t(14;18); some have Bcl-2 and Bcl-6 expression; linked to EBV infection; negative TdT Though often localized, they tend to be aggressive extranodal masses; seen in adults and children, can be seen in HIV infection
Burkitt Lymphoma Intermediate sized B-lymphocytes (small-noncleaved cells) CD10, 19, 20, 79a; t(8:14) is characteristic; African form linked to EBV infection; negative TdT Endemic in Africa with mandibular and abdominal involvement; sporadic elsewhere with abdominal involvement; affects mainly children and young adults
High-grade B-cell Lymphoma (small non-cleaved) Burkitt-like Lymphoma Intermediate sized B-lymphocytes (small non-cleaved cells) CD19, 20 Sporadic; may be seen with HIV infection
Precursor T or B-cell Lymphoblastic Lymphoma/Leukemia (Lymphoblastic Lymphoma) Intermediate sized lymphocytes in a diffuse pattern B-cells are CD19, 20, sometimes CD10; T-cells are CD3 and 8; all are TdT positive Seen in children and adolescents; T-cell type often in mediastinum; very aggressive and can progress to acute lymphocytic leukemia
Mantle Cell Lymphoma Small to medium sized B cells CD 19, 20, 43; t(11;14); Bcl-1 (Cyclin D1) expression Seen in adults in middle age; often advanced at diagnosis and may be extranodal, including multifocal submucosal nodules in bowel
Marginal Zone Lymphoma Small to medium sized B cells CD19, 20, 79a; negative CD5 and 10 Seen in middle aged adults; typically arises in areas of immune activation (Hashimoto thyroiditis, Sjogren syndrome, Helicobacter pylori gastritis); similar lesions asociated with mucosal lymphoid tissue are called MALTomas (mucosa-associated lymphoid tissue tumors); may transform to diffuse large B-cell lymphoma