Case 49
With discussion
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CASE 49 (March 2010)

Clinical information

A 29-year-old man was seen in nephrology clinic because of edema and proteinuria. Two weeks of symptoms.

The patient reported having had 3 previous episodes of malaria, the last one was 3 years ago; the treatment was complete and the disease disappeared.

On physical examination: good general condition, hydrated. Blood pressure: 120/70 mm Hg., heart rate: 71 bpm. There are not skin lesions. Normal cardiopulmonary auscultation. Edema in lower limbs.

Laboratory tests: blood cells count and coagulation tests: normal. Serum creatinine: 1.5 mg/dL; BUN: 27 mg/dL; creatinine clearance: 74.38 mL/min. Total cholesterol: 403 mg/dL; LDL: 299; triglycerides: 145. Serum total proteins: 3.9 g/dL; serum albumin: 1.3 g/dL. C3: 118 (90-180), C4: 20 (10-20), ANAs: negative; anti-DNA: negative. Viruses B y C: negative. HIV: negative. Hemoparasites: negative. Urinalysis: Proteins: 500 mg/dL; 2-6 leukocytes hpf; erythrocytes: 0-2 hpf; bacteria: few; nitrites: negative. Proteinuria: 9,169 mg/24h.

Renal ultrasound: Normal.

With a diagnosis of nephrotic syndrome a renal biopsy was undertaken; on this there was only 2 glomeruli, both normal; immunofluorescence (3 glomeruli): negative. The renal biopsy was repeated: 14 glomeruli.

See the images.

Figure 1. H&E, X100.

Figure 2. Masson's trichrome stain, X400.

Figure 3. H&E, X400.

Figure 4. Methenamine-silver stain, X400.

Figure 5. The lesion is in the tubular portion of the glomerular tuft. Masson's trichrome stain, X400.

Figure 6. In both images the same glomerulus. H&E, X400.

Figure 7. Direct immunofluorescence using antiserum to IgM, X400. Only this glomerulus showed segmental immunostaining for IgM; other 6 glomeruli were negative.

In total, 2 of 14 glomeruli showed segmental lesion; both near to the tubular neck.
Direct immunofluorescence for IgA, IgG, C3 and C1q: Negative.

What is your diagnosis?

See diagnosis and discussion