CASE 70 (December 2011)
The patient is a 10-year-old boy. He presented with a 8-day history of malaise and edema. Systemic hypertension was detected.
A complete blood count was normal. Serum creatinine 1.8 mg/dL, BUN: 27 mg/dL. Proteinuria: 3.2 g/d (140 mg/m2/h), erithrocytes in urine: 20-30/hpf. C3: 65 mg/dL (90-180), C4: 10.1 mg/dL (10-40), ANA: negative.
A renal biopsy was undertaken. See the images.
Figure 1. H&E, X100.
Figure 2. H&E, X200.
Figure 3. H&E, X400.
Figure 4. Methenamine-silver stain, X400.
Figure 5. Masson's trichrome stain, X400.
Figure 6. Masson's trichrome stain, X1,000.
Figure 7. Masson's trichrome stain, X1,000.
Figure 8. Direct immunofluorescence for IgG, X400.
Figure 9. Direct immunofluorescence for C3, X400.
Figure 10. Direct immunofluorescence for IgM, X400.
Figure 11. Direct immunofluorescence for IgA, X400.
Figure 12. Direct immunofluorescence for C1q, X400.
What the blue arrows indicate in figures 6 and 7?
What is your diagnosis?