Case 58
With discussion
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CASE 58 (December 2010)

Clinical information

The patient is a 23-year-old man with a history of three days of severe pain in the left flank and very dark colored urine. He has presented two similar episodes in the last months; in previous episodes the pain lasted for 6-12 days and was associated to macroscopic hematuria. He has no personal history of disease and there is no history of renal disease in his family.

Pain is radiating to the low back and inguinal region. There are no other symptoms or fever.

A previous complete renal study showed no alterations: normal renal function, no proteinuria and no hematuria (urinalysis was done when he had not pain or macroscopic hematuria). Cystoscopy, renal ultrasound and excretory urography: normal; there are not stones or malformations.

Physical examination: Normal, except for pain with percussion on left flank.

Serum creatinine: 0.7 mg/dL; proteinuria: 340 mg/24h; urinary sediment with >50 RBC/HPF, with erythrocyte casts, no leukocytes or other casts. ANA, ENA, anti-DNA: negative. C3 and C4: normal. Viruses: negative. Antistreptolysins not increased. Other laboratory tests: normal.

With a clinical diagnosis of glomerulonephritis a renal biopsy was made. See the images.

Figure 1. H&E, X100.

Figure 2. H&E, X200.

Figure 3. Methenamine-silver stain, X200

Figure 4. Masson's trichrome stain, X400.

Figure 5. Masson's trichrome stain, X400.

Figure 6. PAS stain, X400.

Figure 7. There were not ultrastructural alterations. Electron microscopy, magnification, X6,000.

Direct immunofluorescence for IgA, IgG, IgM, C3, C1q, kappa and lambda: Negative.

What is your diagnosis?

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