Role of electron microscopy in evaluation of native kidney biopsy: a retrospective study of 273 cases.

INTRODUCTION

Electron microscopy (EM) has been widely utilized in the evaluation of kidney biopsies. However, few recent reports have critically assessed its diagnostic value. The aim of this study is to assess the role and value of EM in the evaluation of native kidney biopsies at our institution.

MATERIALS AND METHODS

A retrospective evaluation of 273 native kidney biopsies performed at our institution over 7 years was done by 2 renal pathologists in order to assess the contribution of EM to the final diagnosis in the knowledge of the light microscopy and immunofluorescence findings.

RESULTS

Electron microscopy had an important diagnostic contribution in 39% of cases, in 17% of which EM was essential for diagnosis. Electron microscopy was essential in the diagnosis of minimal change disease, hereditary nephritis, fibrillary glomerulonephritis, and certain classes of lupus nephritis.

CONCLUSIONS

In a great percentage of kidney biopsies, it was possible to make the diagnosis with certainty based on light microscopy and immunofluorescence findings alone. However, still there are numbers of cases in which EM is essentially needed to reach definitive diagnosis. Therefore, at least a piece of tissue should be kept for EM in appropriate fixative in each case, which could then be performed at the discretion of the pathologist.