Acute malignant myelofibrosis. Report of 3 cases

: This report describes three cases of acute malignant myelofibrosis characterized by pancytopenia, absence of splenomegaly, bone marrow fibrosis with an immature cell proliferation and rapidly fatal outcome. The authors investigated the origin of blast cells with the use of immunohistochemical markers on paraffin embedded material with anti-factor VIII, BNH9 and anti-lysozyme. They studied the expression of megakaryoblastic, erythroblastic and myeloblastic differentiation in these cells. They demonstrated the heterogeneity of blast cells which are capable of differentiating along the three hematologic cell lines. The morphometric study showed the mutilating or systematized character of myelofibrosis. The increase in reticulin fiber density compared with normal bone marrow was not significantly different from two other types of myelofibrosis. It would be interesting to correlate a quantitative parameter with the course of this disease in order to evaluate the prognosis and the treatment.