title: A pathological study of dissecting aneurysm in individuals under forty years of age including a case of a 13 years old boy.
abstract: The author has investigated grossly and microscopically 12 cases (5 males and 7 females) of dissecting aneurysm in individuals under 40 years of age, autopsied during the last 6 years at the Tokyo-to Medical Examiner Office. They composed of 6 cases of Marfan's syndrome, 3 cases of obesity, and one case each of pregnancy, aortitis syndrome, and male pseudohermaphroditism, respectively. The 6 cases other than Marfan's syndrome were also thought to belong to the Marfan group from the gross and microscopic examinations of the aorta. As to the cases of dissecting bleeding of the aorta, Erdheim's idiopathic cystic medial necrosis was as a rule authentical up to date, but the author has never observed the bleeding within the cysts which were said to be formed due to accumulation of metachromatic ground substance. On the contrary, the medial bleeding occurred always in the weakened area in where the elastic fibers were disrupted and disappeared accompanying with the diminution of metachromatic substance. The author assumed that the diminution of metachromatic substance might be the most important etiologic factor of dissecting bleeding of the media and the extension of dissection might occur along such weakened foci of the media.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000784:Aortic Dissection / Q000473:pathology*; D001013:Aorta, Thoracic / Q000473:pathology; D001014:Aortic Aneurysm / Q000473:pathology*; D001824:Body Constitution; D005260:Female; D006801:Humans; D008297:Male; D009206:Myocardium / Q000473:pathology