@entity694 is a rare variant of @entity14 claimed to have a more favorable prognosis than conventional @entity420 . The histopathologic appearance may be difficult to distinguish from poorly differentiated @entity420 . The study aimed to evaluate the diagnostic interobserver agreement and to characterize the immunohistochemical and molecular differences between these two subgroups. Fifteen cases initially classified as @entity189 and 30 cases of poorly differentiated @entity420 were included. Two pathologists reviewed the slides independently without knowledge of the original diagnosis and subgrouped the @entity5 into the two entities. Agreement was reached in 31 of 45 cases (69  %) with kappa   =   0.32. An extensive immunohistochemical panel was performed, and @entity984 , @entity8497 , and @entity817 mutational status was assessed. Of the 31 cases with diagnostic agreement, the expression of only @entity6756 along with corresponding expression of @entity14437 differed significantly (p   =   0.04). A high rate of @entity817 mutations was detected in both subgroups without significant differences. Expression of @entity6756 was superior in dividing the @entity5 into two separate entities with significant differences in @entity2225 (p   =   0.005) expression and in the rate of @entity817 mutations (p   =   0.0035). In conclusion, @entity189 of the colon are difficult to discriminate from poorly differentiated @entity420 even with the help of immunohistochemical and molecular analyses. This raises the question whether these morphological subtypes should be maintained or whether an alternative classification of poorly differentiated @entity14 based on @entity6756 status rather than morphology should be suggested.

XXXX : can the undifferentiated be differentiated?

@entity6756 :: ('4292', 'Gene') :: ['MLH-1'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumors'] @entity984 :: ('3845', 'Gene') :: ['KRAS'] @entity2225 :: ('54474', 'Gene') :: ['CK20'] @entity189 :: ('MESH:D002277', 'Disease') :: ['medullary carcinoma', 'medullary carcinomas'] @entity14437 :: ('5395', 'Gene') :: ['PMS-2'] @entity14 :: ('MESH:D015179', 'Disease') :: ['colorectal adenocarcinomas', 'colorectal cancer'] @entity8497 :: ('4893', 'Gene') :: ['NRAS'] @entity817 :: ('673', 'Gene') :: ['BRAF'] @entity694 :: ('MESH:D003110', 'Disease') :: ['Medullary carcinoma of the colon'] @entity420 :: ('MESH:D000230', 'Disease') :: ['adenocarcinomas', 'adenocarcinoma']
@entity694 :: (MESH:D003110,Disease) :: ['Medullary carcinoma of the colon']
