Renal chromophobe cell carcinoma and paraneoplastic linear IgA bullous dermatosis.

Abstract

A 76-year-old man presented with a generalized purpuric bullous eruption with annular disposition. The patient was not taking any medications. Histological examination of the blister showed a subepidermal bulla with neutrophils (fig. 1, A). Leukocytoclastic vasculitis with fibrinoid necrosis was observed in the superficial dermis. Direct immunofluorescence demonstrated linear IgA and C3 deposits along the basement membrane zone and perivascular deposits of fibrinogen and C3 on the dermal vessels (fig. 1, B). Direct immuno-electron microscopy revealed IgA deposits below the lamina densa. Indirect immunofluorescence and immunoblot examinations of the serum on human epidermis using antihuman IgA and IgG antibodies were negative. The patient was treated with 100 mg. dapsone and 20 gm. clobetasol propionate topical cream daily. The association of vasculitis and linear IgA bullous dermatosis in an elderly patient and the absence of healing of the cutaneous lesions following treatment prompted us to search for a paraneoplastic syndrome. Computerized tomography showed a 6 7 cm. polar tumor of the right kidney. No vascular or nodal involvement was noted. The patient subsequently underwent nephrectomy (fig. 2). Histological examination demonstrated renal adenocarcinoma. Cytoplasm of the tumor cells stained positive with Hale’s iron stain. These characteristics were consistent with a diagnosis of renal chromophobe cell carcinoma. Direct immunofluorescence did not reveal IgA deposits in the glomerulus of the normal bordering kidney tissue and there were no symptoms of glomerulonephritis. The skin lesions gradually cleared 15 days after nephrectomy. The patient had no relapse of cutaneous lesions after 12-month followup. DISCUSSION A neoplasia is estimated to be found in approximately 4.5% of cases of linear IgA bullous dermatosis. Neoplasia has been reported to be associated with this condition primarily in hematological disorders. Association with carcinoma has only occasionally been described. To our knowledge this is the first case of paraneoplastic linear IgA bullous dermatosis associated with renal chromophobe cell carcinoma, and the third case associated with a renal tumor. 1 Paraneoplastic syndromes are present in up to 20% of patients with renal carcinoma. 2 This case can be considered a true paraneoplastic syndrome since the clinical course of the 2 conditions occurred simultaneously. Indeed, the cutaneous lesions cleared within a few days after nephrectomy with no recurrence after 12-month followup. Moreover, the demonstration of IgA deposits in the sublamina densa by immuno-electron microscopy, and the presence of associated leukocytoclastic vasculitis in the dermis have been reported to be observed mainly in paraneoplastic skin disorders. 3 Numerous antigens have been reported to be involved in linear IgA bullous dermatosis, with collagen type VII being the most recently described. 1 In this case the ultrastructural localization of IgA deposits in the sublamina densa corre