Pseudolymphomas simulate lymphomas clinically and/or histologically. The differential diagnosis of lymphomas and pseudolymphomas of the skin is one of the most difficult tasks of dermatopathology. In endemic regions of Borrelia burgdorferi infection, the most common B-cell pseudolymphoma is borrelial lymphocytoma. Similar lesions might be rarely induced by vaccination, insect bite and tattoo. The differen¬tial diagnosis of skin pseudolymphomas further includes a lymphomatoid drug reaction and an inflamma-tory pseudotumor of the skin. Clinical, histopathological and molecular-biologic features of these lesions are summarized.

        Key words: : skin - pseudolymphoma - lymphocytoma cutis - cutaneous lymphoid hyperplasia - Borre¬lia burgdorferi - differential diagnosis