CASE 83 (January 2013)
The patient is a girl, 12 years old, with no medical history. Twenty days of evolution of facial edema subsequently accompanied by leg edema, malaise and hyperpigmented urine. On physical examination there is also high blood pressure: 145/90.
Laboratory: The CBC shows mild normocytic normochromic anemia. Tests for viruses: negative. ANA and ANCA: negative. C3 89 (90-180) and C4 36 (10-40). Serum creatinine: 1.2 mg/dL and BUN: 31 mg/dL. Proteinuria in 24 hours: 2.3 g (73 mg/m2/h), with mild hypoalbuminemia. Urinalysis: 20-30 erythrocytes and 3-4 leukocytes per HPF. Tryglicerides: 217 mg/dL and total cholesterol: 384 mg/dL.
See the images of the renal biopsy.
Figure 1. H&E, X100.
Figure 2. H&E, X200.
Figure 3. H&E, X400.
Figure 4. PAS, X400.
Figure 5. Methenamine-silver stain, X400.
Figure 6. Masson's trichrome stain, X1,000.
Figure 7. Masson's trichrome stain, X1,000.
Figure 8. Immunofluorscence for IgG, X400.
Figure 9. Immunofluorscence for C3, X400.
Direct immunofluorescence for IgA, IgM, C1q, kappa, and lambda: Negative.
What is your diagnosis?