title: Synovial tumefactive extramedullary hematopoiesis associated to polycythemia vera.
abstract: The case of a 66-year-old male patient with a chronic myeloproliferative type polycythemia vera disorder, who after 2 years of evolution is developing a tumefactive extramedullary hematopoiesis (TEH) located in the synovial of the articulation in the right knee, is described. The tumor histologically consists of a relatively lax and edematous synovial structure diffusely infiltrated by mature and semimature hematopoietic cellular population. The simultaneous study of the bone marrow reveals medullar spaces full of hematopoietic cellularity, with a predominance of megakaryocytic and red series, and with the addition of severe reticulin fibrosis, facts that suggest a progression toward myelofibrosis. The TEH developed in tissues without a reticulum endothelial system is very uncommon. We provide data about the first case located in the synovial membrane and we review the literature regarding this pathologic entity.
authors.affiliation: Department of Pathology, Canary University Hospital, Tenerife, Canary Islands, Spain.
authors.forename: Hugo
authors.initials: H
authors.lastname: Alvarez-Argüelles Cabrera
authors.forename: José Luis
authors.initials: JL
authors.lastname: Carrasco Juan
authors.forename: María Candelaria
authors.initials: MC
authors.lastname: García Castro
authors.forename: Manuel
authors.initials: M
authors.lastname: González Gaitano
authors.forename: Alfonso
authors.initials: A
authors.lastname: Bonilla Arjona
authors.forename: Lucio
authors.initials: L
authors.lastname: Díaz-Flores
mesh_terms: D000368:Aged; D006411:Hematopoiesis, Extramedullary; D006801:Humans; D008297:Male; D009372:Neoplasms, Connective Tissue / Q000473:pathology*; D011087:Polycythemia Vera / Q000150:complications*; D055728:Primary Myelofibrosis / Q000209:etiology / Q000473:pathology; D013583:Synovial Membrane / Q000473:pathology*