Nephropathology
   
Case 19
With discussion
 
     
Versión en Español

CASE 19 (September 2007)

Clinical information

An otherwise healthy 49-year-old woman presented with a 7-day history of general malaise, fever and edema. Moreover she related diminution of the urinary volume; she did not have neurological symptoms.

A month before the beginning of these symptoms she presented eritematous skin lesions in lower extremities and fever, received antibiotics by 10 days and cultures of these lesions were negative. One of these lesions was biopsied and a diagnosis of "capillaritis” was done (Figure 9).

On examination: blood pressure: 150/100, heart rate: 90 per minute, no fever, mild pallor, oriented, without neurological alterations, edema in both legs and face. Active lesions in skin were not identified. There is a zone with scar appearance in superior and lateral aspect of the leg. Other lesions were not identified.

In laboratory tests mild normocitic normochromic anemia was detected, without hemolysis; leukocytes and platelet were normal in number; serum creatinine: 12.8 mg/dL; BUN: 580 mg/dL; glycemia: 95 mg%. Urinalysis: proteinuria 300 mg/dL, erythrocytes: 50 per HPF, non leukocytes, glucose negative. ANAs, ENAs, anti Ro and anti-La, and ANCAs negative; C3: 65 (90-180), C4: 16 (10-40); tests for hepatitis B and C, and HIV: negative. AELOs: increased; anti DNasa negative.

Renal ultrasound: kidneys increased of size and with good corticomedullary differentiation.

Interdaily hemodialysis was performed in the first days. Three days after admission at hospital the patient presents somnolence, time and space disorientation, dysarthria, and behavioural changes. Brain magnetic resonance was done in which “hyperintensity in cerebral bulb” is detected and “pontine myelinolysis” is diagnosed; clinical neurological alteration has remained almost two months after its initial presentation, although, according to some examiners, “with mild improvement”; there is less somnolence but the patient is apathetic, temporo-space disorientation persist and the patient is in her bed all the time.

What is your clinical diagnosis?

A renal biopsy was undertaken: 10 glomeruli, one globally sclerosed, another one with segmental sclerosis (Figure 4), in the other glomeruli there is cellular mesangial proliferation (between mild and severe). There is not necrosis, karyorrhexis nor crescents. In tubules and interstitium there are the changes seen in Figures 1, 5, and 6.

See the images.

Figure 1. H&E, X200.

Figure 2. Masson's trichrome stain, X400.

Figure 3. Masson's trichrome stain, X400.

Figure 4. Masson's trichrome stain, X400.

Figure 5. PAS stain, X400.

Figure 6. Methenamine-silver stain, X400.

Figure 7. Left and right: Direct immunofluorescence using antiserum to C3, x400. Staining was diffuse.

Figure 8. Left: Direct immunofluorescence using antiserum to IgG, x400; and right: Direct immunofluorescence using antiserum to IgA, x400. Staining was diffuse for both IgG and IgA.

Immunofluorescence for IgM and C1q: Negative.

Figure 9. H&E, X400. There are erythrocyte extravasation and mild mononuclear cell infilrates, but true vasculitis was not found. This case was diagnosed as "capillaritis" by a dermatopathologist. "Capillaritis" is a nonspecific change.

What is your diagnosis?

See diagnosis and discussion

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