The Pathologist and the Phenotype of Hereditary Colorectal Cancer

Abstract

The aim of this review is not to provide a morphological description of each form of colorectal cancer family syndrome. The aim is to explain to a readership that is mainly from a non-pathology background why, when faced with a tissue sample or surgical specimen, it is extremely difficult to extract information that is comprehensive and maximizes the potential for informing the clinical and basic science researcher as well as guiding clinical management. The usual description of a colorectal tumor focuses on its histogenetic type. However, the microscopic appearances of polyps and cancers in cancer family syndromes frequently differ from the appearances of their sporadic counterparts. Even before considering these differences, it is necessary to deconstruct the formal description of biopsied or resected surgical specimens into its basic elements. With respect to polyps, the parameters in question include size, macroscopic appearances, number, anatomic location, and even the synthesis of findings accumulating over time. In critically analyzing these parameters, including the mechanisms underlying their marked phenotypic variation, the full scale of task faced by the pathologist is brought into focus.