The prognostic importance of histologic classifications of @entity6732 is controversial. Evidence suggests that difficulties in reproducibility affect prognostic studies. Two thoracic pathologists independently classified 80 cases of type A or B3 @entity704 according to World Health Organization (WHO) classification. Ki-67 @entity894 ( @entity894 ) was used to identify cutoff points between WHO types. Recursive partitioning (Rpart) and ad hoc methods separated the data points. The pathologists agreed on type A (n = 31), type B3 (n = 21), and @entity704 (n = 14). Ki-67 @entity894 differed between types A and B3 (P < .001) and between @entity704 (P < .001) or type B3 (P = .001). Mitotic activity differed between @entity704 (P < .001) or type B3 (P < .001). Rpart revealed Ki-67 @entity894 greater than 14.0% only in @entity704 ; cases with Ki-67 @entity894 less than 5.1% did not represent @entity704 . Ad hoc analysis showed Ki-67 @entity894 greater than or equal to 13.5% represents @entity704 ; only type A had Ki-67 @entity894 less than 2%. The pathologists disagreed on histologic type in 14 cases. In 11 of 14 cases with available Ki-67, the Rpart method predicted the WHO type; in 7 of 14 cases, the ad hoc method predicted the WHO type. In conclusion, Ki-67 @entity894 is helpful in differentiating @entity6732 , with Ki-67 @entity894 less than 2% and greater than or equal to 13.5% distinguishing @entity704 , respectively.

Diagnostic significance of cell kinetic parameters in World Health Organization type A and B3 XXXX and @entity704 .

@entity6732 :: ('MESH:D013953', 'Disease') :: ['thymic epithelial neoplasms'] @entity704 :: ('MESH:D013945', 'Disease') :: ['thymic carcinoma and type A', 'thymic carcinoma', 'thymoma and thymic carcinoma', 'type A thymoma and thymic carcinoma'] @entity894 :: ('MESH:C566784', 'Disease') :: ['labeling index', 'LI']
@entity704 :: (MESH:D013945,Disease) :: ['thymomas']
