IPLab:Lab 6:Glomerulonephritis

Clinical Summary

During the course of a routine physical examination two months prior to admission, this 57-year-old white male was noted to have a lesion in the upper lobe of the right lung. Initially, he was treated for two weeks with ampicillin. He was then admitted to an outside hospital for further study. All studies including sputum studies for tubercle bacilli, bronchial washings, and bronchoscopy were negative and he was discharged. Review of systems revealed the presence of mild dyspnea on exertion, accompanied by a slightly productive cough. Of interest was the fact that the patient had been PPD positive for the past 4 to 5 years, but this had never been evaluated. On this hospital admission, physical and laboratory examinations were negative. Radiographic examination of the chest revealed a 2 x 2-cm density in the right lower lung field. Several small cavities were identified in this area on CT scan.

Autopsy Findings

The patient underwent a thoracotomy, at which time a portion of the upper lobe of the right lung was removed. Examination of the cut surface revealed small white nodules measuring up to 0.2 cm in diameter.

Images

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  This is a low-power photomicrograph of a saggital section of end stage chronic glomerulonephritis (GN). Note the marked thinning of the cortex (arrow).
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  This is a higher-power photomicrograph of hyalinized glomeruli (arrows) and glomeruli with thick basement membranes.
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  This is a higher-power photomicrograph of hyalinized glomeruli (1) and glomeruli with thickened basement membranes (2).
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  This is a photomicrograph of interstitial and vascular lesions in end stage renal disease.
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  This is an immunofluorescent photomicrograph of granular membranous immunofluorescence (immune complex disease). The antibody used for these studies was specific for IgG.
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  This is an electron micrograph of subepithelial granular electron dense deposits (arrows) which correspond to the granular immunofluorescence seen in the previous image.
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  This is a photomicrograph of a glomerulus from another case with acute poststreptococcal glomerulonephritis. In this case the immune complex glomerular disease is ongoing with necrosis and accumulation of neutrophils in the glomerulus.
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  This immunofluorescent photomicrograph of a glomerulus from a case of acute poststreptococcal glomerulonephritis shows a granular immunofluorescence pattern consistent with immune complex disease. The primary antibody used for this staining was specific for IgG; however antibodies for complement would show a similar pattern.
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  This electron micrograph demonstrates scattered subepithelial dense deposits (arrows) and a polymorphonuclear leukocyte in the lumen.
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  For comparison this is an immunofluorescent photomicrograph of a glomerulus from a patient with Goodpasture's syndrome. The linear (arrows) immunofluorescence is characteristic of Goodpasture's syndrome.

Mycobateria grow very slowly on culture plates, with cultures requiring up to 6 weeks for a positive finding. In lieu of cultures, a more rapid diagnostic test is the PPD--purified protein derivative of tuberculosis--test. PPD is injected under the skin of an individual and then the area is reexamined in 48-72 hours for signs of an inflammatory reaction. A positive test indicates previous exposure to M. tuberculosis.

A thoracotomy is a surgical procedure in which an opening is made in the chest wall.