|  |  | CASE 59 (January 2011) Clinical information A previously healthy 45-year-old man 
        went to the doctor because of malaise, which had developed in the last 
        week. The patient reported having had a mild left ankle sports injury 
        20 days earlier causing him pain and edema, which had almost disappeared.  On physical examination, mild legs edema 
        was present. There was not hypertension or other clinical alterations. On laboratory tests, the white-cell count 
        was 7200/mm3, erythrocyte sedimentation rate: 7 mm/h, the hematocrit was 
        39.2%, and the platelet count 227,000/mm3. Serum creatinine was markedly 
        increased: 7.5 mg/dL; BUN: 98 mg/dL.  With a diagnosis of acute renal failure, 
        other laboratory test were ordered and a renal biopsy was undertaken. 
        See the images. 
 Figure 1. 
        H&E, X200. 
 Figure 2. 
        H&E, X200.  
 Figure 3. 
         Masson's 
        trichrome stain, X200. 
 Figure 4. 
         H&E, 
        X400. 
 Figure 5. 
         H&E, 
        X400. 
 Figure 6. 
         H&E, X200. 
 Figure 7. 
        H&E, X400. 
 Figure 
        8. Methenamine-silver stain,  
        X400 
 Figure 
        9.  Methenamine-silver 
        stain,  X400  Direct immunofluorescence for IgA, IgG, 
        IgM, C3, C1q, kappa and lambda: negative. What is your diagnosis?  See 
        diagnosis and discussion [Top] |  |