Fig. 4: Immunohistochemical analysis of IDH2 R172 is highly sensitive and specific for the detection of IDH2 R172 hotspot mutations in tall cell carcinomas with reversed polarity.

a Frequency of IDH2 R172 and PIK3CA hotspot mutations and expression of IDH2 R172 by immunohistochemistry in tall cell carcinomas with reverse polarity (n = 14), intraductal papillomas (n = 13), solid papillary carcinomas (n = 16) and encapsulated papillary carcinomas (n = 5). IDH2 R172 and PIK3CA mutational status and immunoreactivity for IDH2 R172 are color-coded according to the legend. b Representative Sanger sequencing electropherograms of the IDH2 R172 (left) and PIK3CA H1047 (right) hotspot loci in intraductal papilloma IDP12. Representative (c, e) hematoxylin and eosin and (d, f) IDH2 R172 expression photomicrographs of (c, d) the intraductal papilloma IDP12 and (e, f) solid papillary carcinoma PC14.