title: Cyclic thrombocytopenia and polycythemia vera.
abstract: A periodic fall of platelet number characterizes an acquired pathological condition named cyclic thrombocytopenia. We describe an unusual case of polycythemia vera in which the episodes of thrombocytopenia were followed regularly by thrombocytosis. The period of platelet count fluctuation was about 50 days, with the counts ranging from 34 to 820 x 10(9)/l. Bone marrow megakaryocytes were decreased in number during platelet nadir. Circulating thrombopoietin levels fluctuated out of phase with the platelet count. We suggest that at least some cases of polycythemia vera may have an unstable hematopoietic stem cell pool in nature, which could contribute to the development of unprovoked cyclic thrombocytopenia.
authors.affiliation: Department of Medicine II, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. kkoji@m.ehime-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Kojima
authors.forename: N
authors.initials: N
authors.lastname: Fujii
authors.forename: E
authors.initials: E
authors.lastname: Omoto
authors.forename: S
authors.initials: S
authors.lastname: Nose
authors.forename: M
authors.initials: M
authors.lastname: Yoneyama
authors.forename: Y
authors.initials: Y
authors.lastname: Sugii
authors.forename: H
authors.initials: H
authors.lastname: Hiramatsu
authors.forename: M
authors.initials: M
authors.lastname: Chikatsune
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.forename: S
authors.initials: S
authors.lastname: Takata
authors.forename: T
authors.initials: T
authors.lastname: Itoshima
authors.forename: M
authors.initials: M
authors.lastname: Tanimoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001854:Bone Marrow Cells / Q000473:pathology; D006801:Humans; D008297:Male; D008533:Megakaryocytes / Q000473:pathology; D010507:Periodicity; D010976:Platelet Count; D011087:Polycythemia Vera / Q000097:blood / Q000150:complications* / Q000473:pathology; D012008:Recurrence; D013921:Thrombocytopenia / Q000097:blood / Q000150:complications* / Q000473:pathology; D013922:Thrombocytosis / Q000097:blood / Q000150:complications / Q000473:pathology; D013926:Thrombopoietin / Q000097:blood
chemical_list: D013926:Thrombopoietin