title: An autopsy case of myocardial infarction due to idiopathic thrombotic thrombocytopenic purpura.
abstract: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder characterized by systemic platelet-von Willebrand factor aggregation, organ ischemia and profound thrombocytopenia. In this report, we describe an autopsy case of a 77-year-old Japanese man diagnosed with idiopathic TTP. He had no history of cardiovascular disease symptoms, such as chest pain, ST segment elevation, and elevation of cardiac enzyme levels, except arrhythmia. The patient suddenly died despite receiving many treatments. On autopsy, macroscopically and microscopically, acute and chronic myocardial infarction manifested as petechiae and fibrotic foci and covered a wide area in the myocardium, including the area near the atrioventricular node. The microthrombi in the small arterioles and capillaries were platelet thrombi, which showed positive results for periodic acid-Schiff stain and factor VIII on immunohistochemical staining. The cause of the sudden death was suspected to be myocardial infarction, including a cardiac conduction system disorder due to multiple platelet microthrombi. Asymptomatic myocardial infarction is an important cause of death in TTP. Therefore, the heart tissue, including the sinus-atrial node and the atrioventricular node, should be microscopically examined more closely in autopsy cases of patients with TTP who experienced sudden death of TTP. This report is a critical teaching case considering that its cause of sudden death may be arrhythmia due to a myocardial infarction including cardiac conduction system disorder by platelet microthrombi.
  The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2113354005156739.
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan. t-tasaki@m2.kufm.kagoshima-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tasaki
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan. sousuke@med.uoeh-u.ac.jp.
authors.forename: Sohsuke
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan. nabe11679@yahoo.co.jp.
authors.forename: Atsunori
authors.initials: A
authors.lastname: Nabeshima
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan. noooooogle@yahoo.co.jp.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan. aya.y0116@gmail.com.
authors.forename: Aya
authors.initials: A
authors.lastname: Nawata
authors.affiliation: Pathology and Oncology, University of Occupational and Environmental Health, Kitakyusyu, Japan. hisaoka@med.uoeh-u.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Hisaoka
authors.affiliation: Department of Pathology, Fukuoka Wajiro Hospital, Fukuoka, Japan. yasu3219@med.uoeh-u.ac.jp.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sasaguri
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan. toshi-n@med.uoeh-u.ac.jp.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Nakayama
mesh_terms: D000368:Aged; D058070:Asymptomatic Diseases; D001281:Atrial Fibrillation / Q000209:etiology; D001344:Autopsy; D015415:Biomarkers / Q000032:analysis; D003331:Coronary Vessels / Q000737:chemistry / Q000473:pathology; D017809:Fatal Outcome; D005355:Fibrosis; D006329:Heart Conduction System / Q000737:chemistry / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis / Q000209:etiology*; D009206:Myocardium / Q000737:chemistry / Q000473:pathology; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications* / Q000175:diagnosis
chemical_list: D015415:Biomarkers