Dissecting aneurysms of the aorta.

Up to 1934 only six of the 300 cases of dissecting aneurysm of the aorta described in the literature had been diagnosed ante mortem (Shennan, 1934). Many correctly diagnosed cases have since been reported (with decreasing pride) and the condition is now well enough recognized in general medical practice for cases to be reported only when they present some unusual or particularly instructive feature. Dissecting aneurysm has been wrongly diagnosed ante mortem as syphilitic aortic disease on many occasions and confusion can also occurpost mortem. The importance of this differential diagnosis tends to be overlooked, especially in the standard textbooks on syphilology and cardiology, and even in recent monographs on syphilitic cardiovascular disease. If the current decline in the incidence of syphilis continues, there is likely to be a relative increase in the incidence of dissecting aneurysm-a phenomenon that has already been noted (Simpson, 1947; Newcomb, 1953). A personal, salutary experience has prompted a review of the subject from this point of view. The pathogenesis, symptomatology, and diagnosis of dissecting aneurysm are briefly described first of all (giving references for further study), three illustrative cases are reported, and the differential diagnosis from syphilis is then discussed.