Acute renal failure in a young woman with Fisher-Evans' syndrome.

A young female with Fisher-Evans' syndrome and a previous melanoma developed acute renal failure with generalized lymphoadenopathy and fever. The appearance of renal lesions is common in the course of several hematological disorders, but is unusual in Fisher-Evans' syndrome. Fisher-Evans' syndrome, defined as Coombs' positive hemolytic anemia and immune thrombocytopenia, is more frequently associated with the other autoimmune diseases, but not with renal involvement. In our case report, having excluded amyloidosis, myeloma, interstitial nephritis and sepsis, the rapid involvement of renal function with enlarged renal size seemed to suggest renal lymphoma. However, the lack of a monoclonal T-lymphocyte population in the renal tissue and peripheral blood, along with a clinical course characterized by a rapid reversibility of acute renal failure made this diagnosis rather an unlikely one. Polyclonal lymphocyte infiltration in a patient with a persistent autoimmune disease made us suspect a hyperimmune reaction. This syndrome is a non-neoplastic proliferation of B-cells involving an exaggeration of lymphocyte transformation. However, the clinical course is progressive and fatal, and can trigger a lymphoproliferative systemic disease. In our patient, two elements led us to suspect it was not a typical hyperimmune syndrome: first, polyclonal lymphocytes had massively infiltrated the kidney and, secondly, the clinical outcome was extremely favorable. Therefore, we were faced with an "atypical" and "singular" hyperimmune reaction with renal involvement, polyclonal proliferation of T-lymphocytes that had exhausted itself over time. Infective or toxic agents or drugs such as cyprofloxacin could have triggered the phenomenon, in the presence of a favorable condition such as Fisher-Evans' syndrome.