Paraneoplastic pemphigus with clinical features of lichen planus associated with low-grade B cell lymphoma

Background Neoplasia-induced lichen planus is described as a cell-mediated reaction to unknown epithelial antigens. Paraneoplastic pemphigus (PNP), characterized by the presence of a specific array of autoantbodies, probably represents a different form of presentation of the same autoimmune syndrome where the mucocutaneous; expression depends on the dominant pathologic mechanism, Methods The authors report a case of PNP with predominant lichen planus-like lesions and review the relevant literature. We observed a 74-year-old female with vesico-bullous, erosive, target-shaped and flat papular lichenoid lesions on the lower legs, palms and soles, evolving for 3 weeks. Histopathology revealed a lichenold dermatitis. Direct immunofluorescence showed C3 deposition around keratinocytes; and epidermal IgG intranuclear deposition. Indirect immunofluorescence revealed circulating IgG with intercellular staining on rat bladder substrate. Immunoblotting demonstrated bands of 130, 190, 210 and 250 kDa antigens. A pararenal B cell lymphoma was found. Results Oral corticotherapy with 40 mg prednisolone daily was initiated with a good cutaneous response. Four months later, cyclophosphamide (50 mg/day) was introduced because of a discrete enlargement of the pararenal mass. The patient died on the seventh month of follow up as a result of respiratory insufficiency. Conclusion PNP has different forms of presentation and the lack of a consensus about diagnostic criteria may contribute to underdiagnosed cases. Advances on the knowledge of the sensitivity and specificity of diagnostic criteria have allowed a better accuracy of diagnosis.