title: Acute myelofibrosis. Immunohistochemical study of four cases and comparison with acute megakaryocytic leukemia.
abstract: Four cases of acute myelofibrosis are contrasted to three cases of acute megakaryocytic leukemia. The cases were clinically indistinguishable. Light microscopic examination of hematoxylin and eosin-stained bone marrow biopsy specimens from the cases of acute myelofibrosis showed a trilinear proliferation of mature and immature hematopoietic cells, increased numbers of mature magakaryocytes, and marked fibrosis. In contrast, the blast cells in the cases of acute megakaryocytic leukemia showed a continuous spectrum of differentiation from small blasts to megakaryoblasts. Immunoperoxidase staining showed the blast cells in all three cases of acute megakaryocytic leukemia to be strongly positive for Factor VIII, a marker of megakaryocytic differentiation. These same blasts did not stain with markers of myelomonocytic (lysozyme), lymphocytic (Hle), and myeloid (Leu-Ml) differentiation. In contrast, the blast cells in all four cases of acute myelofibrosis were Factor VIII, Hle, and Leu-Ml negative but did occasionally stain with anti-lysozyme.
authors.affiliation: Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland.
authors.forename: R H
authors.initials: RH
authors.lastname: Hruban
authors.forename: F P
authors.initials: FP
authors.lastname: Kuhajda
authors.forename: R B
authors.initials: RB
authors.lastname: Mann
mesh_terms: D000208:Acute Disease; D000328:Adult; D001773:Blood Cells / Q000473:pathology; D001853:Bone Marrow / Q000473:pathology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D055728:Primary Myelofibrosis / Q000097:blood / Q000276:immunology* / Q000473:pathology; D013920:Thrombocythemia, Essential / Q000276:immunology* / Q000473:pathology