A patient with follicular B-cell lymphoma presented with erythroderma associated with cutaneous and mucosal blisters. Histologic and direct immunofluorescence analysis of lesional skin showed a typical pattern of paraneoplastic pemphigus (PNP). Interestingly, indirect immunofluorescence on rat bladder was negative and immunoblot analysis of the patient's serum on epidermal extracts demonstrated antiepidermal antibodies that only recognized the pemphigus vulgaris antigen desmoglein 3, with no antibodies directed against the different proteins of the plakin family. To our knowledge this has never been reported in the literature. It exemplifies the overlap between pemphigus vulgaris and PNP and the pathogenic role of anti-desmoglein 3 antibodies in PNP. Moreover, it underscores the need to consider clinical, histologic, and immunologic features for the diagnosis of PNP. (J Am Acad Dermatol 2000;43:714-7.)