title: Extensive portal and mesenteric vein thrombosis in a young man with Klinefelter's syndrome.
abstract: Klinefelter's syndrome (KS) is a unique physical condition characterized by tall stature, eunuchoid body proportions, gynecomastia, and azoospermia, in addition to an extra X chromosome. In contrast to the original description, symptoms or physical findings can be extremely varied. KS is the most common chromosomal disorder, with an incidence of 1 in 500 males and is also the most commonly undiagnosed chromosomal disorder. Here, we present the case of a 26-year-old man with KS, who visited our hospital with complaints of abdominal pain and fever. On a routine physical examination, he did not differ from a normal karyotype male. Computed tomography showed extensive portal and mesenteric vein thrombosis (PMVT). It is well known that KS is frequently associated with venous thrombosis, but KS with PMVT has rarely been reported. Approximately one-third of PMVT is idiopathic, but this case suggests the possibility that undiagnosed KS is one of the causes of PMVT, as some individuals with KS are not easily distinguishable from those with the normal karyotype.
authors.affiliation: Department of Gastroenterology, Kushiro City General Hospital, Kushiro             First Department of Internal Medicine, Sapporo Medical University, Sapporo, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Matsunaga
authors.forename: Akira
authors.initials: A
authors.lastname: Goto
authors.forename: Hideki
authors.initials: H
authors.lastname: Wakasugi
authors.forename: Ayako
authors.initials: A
authors.lastname: Itoh
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yonezawa
authors.forename: Miki
authors.initials: M
authors.lastname: Itoh
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Kazuya
authors.initials: K
authors.lastname: Suzuki
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.forename: Keiko
authors.initials: K
authors.lastname: Ushijima
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Shinomura