The OHSU Renal Biopsy Service
Dividing the limited biopsy specimen:
When the biopsy sample is not sufficient to be divided into the three parts as described for the adequate biopsy specimen, a judgment will be necessary as to which one or two of the three recommended studies to request. The following comments are offered to help guide your judgment:
- Light microscopy (LM) has highest priority in nearly all circumstances.
- Immunofluorescence microscopy (IF) may have priority in the evaluation of rapidly progressive glomerulonephritis.
- IF is more important than electron microscopy (EM) in most settings of acute renal failure
- EM is more important than IF in most settings of pediatric nephrotic syndrome
- IF cannot be performed on tissues fixed for LM or EM
- The IF tissue can be reprocessed for:
Light microscopy (many architectural abnormalities can be identified, but cellular artifacts are usually severe)
Electron microscopy (cellular detail is lost but matrix, basement membranes and deposits are usually preserved)
- The LM specimen can be reprocessed for EM with usually satisfactory results.
- Renal medulla is suitable for IF studies in the evaluation of allograft rejection.