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Updated: Apr 15, 2026
Quantification of Colonic Stem Cell Mutations
Published on: September 25, 2015
PHH3 as an Ancillary Mitotic Marker in Gastrointestinal Stromal Tumors
Yooju Shin1, Jiyeon Hyeon1, Boram Lee1
1Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University College of Medicine, Seoul, Korea.
Background:
Counting mitoses is subjective and time-consuming. The adjunctive diagnostic utility of a recently reported mitotic marker, phosphohistone H3 (PHH3), was investigated in gastrointestinal stromal tumors (GISTs).
Methods:
We reviewed 77 GISTs for several proliferative indices. These included the mitotic count per 50 high power fields (HPFs), the immunohistochemical Ki- 67 labeling index and the immunohistochemical PHH3 mitotic index (MI). For comparison, Spearman's rank correlation and interclass correlation coefficient were used.
Results:
Mitotic counts ranged from 0-138 (mean, 7.57±2.34) and the PHH3 MI ranged from 0-126 per 50 HPFs (mean, 9.61±2.27). We found a positive correlation between mitotic counts and PHH3 MI (r=0.810, p<.001). The inter-observer correlation coefficient for three participants was 0.975 for mitotic counts and 0.940 for the PHH3 MI. When using the PHH3 MI instead of mitotic counts in the Armed Forces Institute of Pathology (AFIP) stratification criteria, 10 cases were reclassified. In one patient with a mitotic count of 2 and a PHH3 MI of 6 per 50 HPFs, distant metastasis occurred.
Conclusions:
In GISTs, the PHH3 MI correlated adequately with mitotic counts and can be used as a useful adjunctive to count mitotic figures efficiently.
