title: Redistribution of granulopoiesis from extramedullary territories to bone marrow in a case of spent polycythemia treated with alkylating agents.
abstract: We report a case of splenectomized spent polycythemia, where under the influence of alkylating agents (busulfan or chlorambucil), a true redistribution of granulopoiesis appeared. Before treatment, granulopoiesis was confined to the liver (within the portal spaces and the sinusoids), whereas bone marrow was depleted of any hematopoiesis, being the site of a mutilating fibrosis; the blood concentration of granulomonocytic colony-forming cells (GM-CFCs) was high. After a year of discontinuous treatment an intense granulopoiesis was present in bone marrow, comprising more than 90% of the hematopoietic cells, whereas circulating colony-forming cells were low to nil. This phenomenon was long-lasting, since after another year of treatment, a third bone marrow biopsy revealed the persistence of an active granulopoiesis. During the last year of treatment, the treatment was continuous with chlorambucil. After 6 months a decrease in polymorph and platelet values appeared and treatment had to be interrupted. Death supervened one month after treatment interruption. Histological examination revealed the lack of any intrahepatic hematopoiesis whereas bone marrow granulopoiesis was active but presented gross maturation abnormalities. The results obtained in this case permit discussion of some aspects of the physiopathology of myelofibrosis, and particularly the genesis of extramedullary hematopoiesis in this clonal disease.
mesh_terms: D001706:Biopsy; D001772:Blood Cell Count; D001853:Bone Marrow / Q000473:pathology*; D002066:Busulfan / Q000627:therapeutic use; D002699:Chlorambucil / Q000627:therapeutic use; D005260:Female; D006098:Granulocytes / Q000166:cytology*; D006801:Humans; D007621:Karyotyping; D008099:Liver / Q000473:pathology; D008875:Middle Aged; D011087:Polycythemia Vera / Q000188:drug therapy* / Q000473:pathology; D013156:Splenectomy; D013234:Stem Cells / Q000032:analysis*
chemical_list: D002699:Chlorambucil; D002066:Busulfan