Renal biopsy specimens

Taking a kidney biopsy is not a trivial procedure. The sample is almost invariably smaller than the pathologist would like. Investigation usually requires division into even smaller samples to permit the application of specialist techniques. In some cases the biopsy is taken not for diagnosis, but to assess the extent of tissue damage. The clinical need is sometimes extremely urgent. These features all underline the crucial importance of collaboration between pathologist and nephrologist if maximum benefit is to be obtained from such very small samples. Consequently, in deciding what to do with a renal biopsy, flexibility and thought are required rather than a single prescribed list of procedures. This article, written after extensive international consultation, represents an attempt to define current best practice in the laboratory handling of renal biopsy specimens, while not neglecting the need to tailor processing to the individual needs of each case.