Current nomenclature and histopathological criteria for assessment of the noninflammatory degenerative diseases of the aorta.

A histopathological examination of the surgical specimen of the aorta usually follows a surgical reconstruction of the aortic aneurysm or dissection. Among the adults, the frequent cause of the aneurysm development is a severe atherosclerosis, while in children the aneurysm or dissection usually come as a complication of genetic syndromes. The common microscopical denominator of those diseases is a medial degeneration of variable degree. For a long time, a terminology of microscopical structural alterations used to be subjective and unsettled. In 2016, the first international guidelines for the histopathological assessment of the non-inflammatory degenerative diseases of the aorta were established. They introduced unified nomenclature, defined individual microscopic alterations and implemented a three-tier grading system. This work aims at practical aspects of the microscopical assessment and interpretation of the degenerative processes in the aorta with regards to the aforementioned consensus.