The pseudolymphoma of the skin has the architectural and cytological features of a neoplastic proliferation of lymphoid tissue but pursue a benign course. Cutaneous B cell pseudolymphoma (CBPL) shares many histopathologic and clinical features with cutaneous B cell lymphoma (CBCL). Therefore, the differentiation between CBPL and CBCL is often very difficult, but it is important because each of them has a different therapeutic consequence. Recently, immunoglobulin gene rearrangement is considered as a reliable technique for differentiation of CBPL with CBCL.