BACKGROUND:Grading upper tract urothelial carcinomas (UTUC) in cell blocks with small distorted tissue fragments can be challenging; interobserver agreement is poor among pathologists.
Mitotic figure (MF) counting along with nuclear features is important in grading these tumors. We evaluated the use of the mitotic-specific marker phosphohistone H3 (PHH3) as an adjunct to hematoxylin and eosin (H&E) stain for grading UTUC in cell blocks.
METHODS:Formalin-fixed, paraffin-embedded tissues from the cell blocks of 61 UTUC were stained with H&E and PHH3 antibody. The grading of tumors was performed independently by 3 pathologists, on both H&E-stained and PHH3 plus H&E-stained slides. The grading system used was the 1973 WHO 3-point grading system. Gradings were compared by all the pathologists for H&E staining versus PHH3 plus H&E staining with the Stuart-Maxwell test of marginal homogeneity that accounts for the matched data.
RESULTS:The average pairwise agreement by H&E alone was 55%, and 80% by PHH3 plus H&E.
CONCLUSION: By adding PHH3 immunostain to the H&E, the agreement in grading the carcinomas among the 3 pathologists improved dramatically. PHH3 immunostain may play an important role in grading UTUC in small cell block samples.
Written by:
Solomides CC, Birbe RC, Nicolaou N, Bagley D, Bibbo M. Are you the author?
Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
Reference: Acta Cytol. 2012;56(3):285-8.
PubMed Abstract
PMID: 22555531
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