Case 114
With discussion
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CASE 114 (August 2015)

Clinical information

A 57-year-old woman presented with nonspecific symptoms of several months: weakness and malaise, polyuria and polydipsia. On physical examination no alterations were described.

Laboratory tests: Normal blood count, serum creatinine 0.9 mg/dL, BUN 16 mg/dL. Na 138 mEq/L, K 2.8 mEq/L, Cl 113 mEq/L, HCO3 14 mEq/L. Normal glycemia: Tests for autoimmunity: negative or normal. HIV and hepatotropic viruses: Negative. Cryoglobulins were negative. Urinalysis: proteinuria: 790 mg/24h, erythrocytes: 2-3/hpf, glucosuria 1+. Calcium 9.8 mg/dL, alkaline phosphatase 218 IU/L (44-147); phosphate 0.9 mg/dL (2.4-4.3); urinary phosphate 124 mg/24 hours. PTH: 38 pg/mL (15-65); pH 7.24 (7.35-7.45), pCO2 31 mm Hg (36-47), PO2 129 mm Hg (65-95) (Fanconi syndrome).

A Renal biopsy was done, see the images.

Figure 1. H&E, X100.

Figure 2. H&E, X400.

Figure 3. H&E, X400.

Figure 4. H&E, X400.

Figure 5. Methenaime-silver stain, X400.

Figure 6. Masson's trichrome stain, X400.

Figure 7. Masson's trichrome stain, X400.

Figure 8. Immunofluorescence for kappa light chain, X400.

Figure 9. Immunofluorescence for lambda light chain, X400.

Immunofluorescence for IgA, IgG, IgM, C3 and C1q: Negative.

What is your diagnosis?

See diagnosis and discussion