Mucocutaneous autoimmune syndrome following fludarabine therapy for low-grade non-Hodgkin's lymphoma of B-cell type (B-NHL).

A 40-year-old patient with low-grade B-NHL developed a generalized macular-papular rash following the first cycle of fludarabine treatment which progressed to a complete epidermal necrolysis following the second cycle. Clinical symptoms and the results of the direct and indirect immunofluorescence were consistent with a mucocutaneous autoimmune syndrome (pemphigus). Immunohistochemical analysis demonstrated a dense epidermal infiltration of CD8+ lymphocytes associated with the histological features of single-cell necrosis of keratinocytes. Early and aggressive immunosuppressive treatment with steroids, cyclophosphamide, and high-dose immunoglobulins resulted in regression of symptoms and complete reconstitution of epidermal integrity. The malignant lymphoma has completely regressed. The findings suggest a fludarabine-induced defect in immunosurveillance--resulting in the uncontrolled activation of autoaggressive T-cell clones--as a pathogenetic mechanism of this life-threatening dermatological complication.