[Development of molecular-pathologic entities of colorectal cancer]

Molecular-pathologic tumor entities are characterized by a unique combination of morphological, genetic, molecular and clinical features. Increased molecular subtyping and development of diagnostics towards molecular-pathologic entities can be expected for frequent solid cancer types in the future. Initial steps towards this development are discussed for the subtypes of serrated adenocarcinoma, medullary carcinoma and micropapillary carcinoma of colorectal cancer. Based on current knowledge, medullary carcinoma of the colon is definitely a molecular-pathologic entity. A high-risk-subtype and a low-risk-subtype - but not the whole group - of colorectal serrated adenocarcinomas also fulfill the criteria of a molecular-pathologic entity. In contrast, micropapillary carcinoma shows a distinct infiltrative pattern, which can occur as part of colorectal cancer, but which is not a molecular-pathologic entity in its own right.