Primary cutaneous B-cell lymphomas constitute a significant subset, approximately 25%, of all primary skin lymphomas. They comprise four major clinicopathological entities: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, primary cutaneous diffuse large B-cell lymphoma, leg type, and B-cell lymphomas and lymphoid proliferations associated with immune deficiency and dysregulation. Patients exhibit the formation of cutaneous plaques, nodules, or tumors, which may occur as isolated or clustered lesions. Most primary cutaneous B-cell lymphomas are low-grade malignancies, thereby displaying a proclivity for localized cutaneous involvement without frequent dissemination to lymph nodes or extracutaneous tissues. Nonetheless, there are distinct exceptions to this general rule, such as primary cutaneous diffuse large B-cell lymphoma, leg type (pcDLBCL-LT), which tends to exhibit a more aggressive course and could manifest with disseminated lesions. Similarly, expansive lesion distribution has been documented in cases of immunodeficiency-associated B-cell lymphomas and lymphoproliferative diseases.