CASE 174 (August 2020)

Clinical information

A 69-year-old man, with no personal pathological history, presents progressive, generalized, edema of 8 days of evolution. He does not report respiratory symptoms or fever. Complete nephrotic syndrome is documented, with proteinuria of 8.2 g/24h, hypoalbuminemia, and dyslipidemia. Serum creatinine: 0.9 mg/dL, BUN: 12 mg/dL. Normal blood cell count. Autoimmunity studies: negative or normal. Protein electrophoresis and immunofixation without evidence of paraproteinemia. Studies for infections were negative.

There is no history of hypertension or diabetes. The patient reports that hydroxychloroquine was self-medicated for one week, up to 3 days before the onset of symptoms, to "prevent covid-19".

Kidney biopsy is done. Look at the photomicrographs.

Figure 1. Much of the sample corresponded to normal kidney medulla, H&E, X100.

Figure 2. H&E, X400.

Figure 3. PAS, X400.

Figure 4. Masson's trichrome stain, X400.

Figure 5. Methenamine-silver stain, X400.

Figure 6. EM, original magnification, X1,500.

Figure 7. EM, original magnification, X2,500.

Figure 8. EM, original magnification, X2,500.

Figure 9. EM, original magnification, X2,500.

Figure 10. EM, original magnification, X2,500.

Figure 11. EM, original magnification, X2,500.

Figure 12. EM, original magnification, X4,000.

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

What is your diagnosis?

See diagnosis and discussion

[Top]