Background: During the course of chronic myeloproliferative disorders (CMPD), myelofibrosis (MF) represents a negative prognostic factor. The data concerning the incidence and progression of MF are rather heterogenous.
Objectives: The aim of the study was to evaluate the incidence and progression of MF in cases of CMPD registered in the Consultation Center for Haematopathology Biopsies in Martin Faculty Hospital.
Methods: Fibrotic changes involving bone marrow were evaluated histologically semiquantitatively using reticulin fiber impregnation (method of Gomori). The study included 77 cases of chronic myelocytic leukemia (CML), 99 cases of polycythaemia vera (PV), 38 cases of essential thrombocythaemia (ET), and 126 cases of the fourth type of CMPD, mostly known as myelofibrosis/osteomyelofibrosis type (MF/OMF). The occurrence and degree of MF were evaluated at the time of all primary biopsies; in 52 of cases also in rebiopsy material.
Results: At the time of primary diagnosis, MF occurred in 37/77 (48%) cases of CML, in 27/99 (27.3%) cases of PV, in 8/38 (21%) cases of ET, and in 119/126 (94.4%) cases of MF/OMF. In repeated (secondary) biopsies, the progression of MF or evolution to MF was most common in CML and MF/OMF types.
Conclusions: At the time of the CMPD diagnosis, more than 50% of cases showed the presence of MF. During the course of CMPD, the MF seems to represent a dynamic process evolving the underlying disease. The early diagnosis of MF is important for the selection of the appropriate therapeutic regimen. (Tab. 3, Fig. 2, Ref. 23.)