Identification of Phosphohistone H3 Cutoff Values Corresponding to Original WHO Grades but Distinguishable in Well-Differentiated Gastrointestinal Neuroendocrine Tumors

Table 2

Comparison of histologic grades combined with PHH3 staining and cutoff value of ≥4/10 HPFs.

	Total; (%)	WHO grade				Kappa
		Grade 1	Grade 2	Grade 3
		(%)	(%)	(%)
Grades in replacement of H&E-mitosis by PHH3					<0.001	0.428
Grade 1	86 (61.0)	80 (80.0)	6 (20.7)	0 (0.0)
Grade 2	53 (37.6)	30 (30.0)	23 (79.3)	0 (0.0)
Grade 3	2 (1.4)	0 (0.0)	0 (0.0)	2 (100)
Grades with PHH3 cutoff ≥4/10 HPFs					<0.001	0.810
Grade 1	104 (73.8)	102 (92.7)	2 (6.9)	0 (0.0)
Grade 2	35 (24.8)	8 (7.3)	27 (93.1)	0 (0.0)
Grade 3	2 (1.4)	0 (0.0)	0 (0.0)	2 (100)

HPF, high-power field. significant. value <0.05.