Extranodal Marginal Zone Lymphoma (EMZL lymphoma) is an indolent B-cell lymphoma with a median age at diagnosis of about 60 years. It accounts for 7-8% of all B-cell lymphomas. It can occur in various extranodal sites, including stomach, lung, ocular adnexa, and skin; furthermore, the disseminated disease can be found in 25-50% of cases. Several infectious agents, such as ( ) in the case of gastric Mucosa Associated Lymphoid Tissue (MALT) Lymphoma, can drive the pathogenesis of this cancer, through the autoantigenic stimulation of T cells, but there may also be other factors participating such autoimmune diseases. Initial staging should include total body computed tomography, bone marrow aspirate, and endoscopic investigation if indicated. Fluorescence in situ hybridization (FISH), should be performed to detect the presence of specific chromosomal translocations involving the and genes, which leads to the activation of the signaling pathway. Depending on the location and dissemination of the disease, different therapeutic choices may include targeted therapy against the etiopathogenetic agent, radiotherapy, immunochemotherapy, and biological drugs. The purpose of this review is to illustrate the complex biology and the diagnosis of this disease and to better define new treatment strategies.