| Popis: |
Among primary cutaneous B-cell lymphomas (CBCL), two main clinico-pathologic entities are recognized, i.e. marginal zone lymphoma (MZL), otherwise defined as extranodal MZL, MALT (Mucosa-Associated Lymphoid Tissue) type, and follicle center lymphoma (FCL). They are mostly characterized by indolent course (very limited risk of extracutaneous spread), very good response to non-aggressive treatment (radiotherapy is the gold standard), and excellent prognosis (90% 5-year survival overall). The clinical presentation of MZL and FCL slightly differ concerning site predilection (trunk and upper limbs in the former, headneck and trunk in the latter) and frequency of cases with multiple, non-contiguous lesions (higher in MZL). Histologically, MZL and FCL share the multiphasic evolution of lesions, while some distinctive features are clues to diagnosis and differential diagnosis: CD5-/CD10-/bcl2+ phenotype of neoplastic cells, "colonization" of reactive lymphoid follicles by neoplastic cells, lymphoplasmacytoid and plasma cells at the periphery of nodular infiltrates in MZL; CD5-, CD10 +/-, bcl6+, MUM-1 neg, FOX-P1 neg, IRF4 neg, IgM neg phenotype of neoplastic cells (centrocytes), and neoplastic follicles (in early lesions) in FCL. |
