Background: Idiopathic myelofibrosis (IM) is an infrequent myeloproliferative disorder with few large series published in the medical literature. Information on the characteristics of more recently diagnosed patients with IM is scarce.
Patients and methods: The initial features, evolutive patterns and survival from 106 patients diagnosed with IM in a single institution between 1975 and 1996 were analyzed.
Results: Median age of the series was 64 years (range: 17-89); there were 61 males and 55 females. One third of the patients were asymptomatic at IM diagnosis. The most common presenting symptoms were related to hypermetabolism, anemia and splenomegaly. A palpable spleen was noted in 85% of patients, and 66% had hepatomegaly. Anemia was the most frequent hematologic abnormality (50% of cases). Bone marrow biopsy showed cellular phase IM in 50 patients, IM without osteosclerosis in 39, and osteosclerotic IM in the remaining 17. Evolution into acute leukemia was seen in 14 patients (actuarial probability at 7 years: 20%, 95% CI: 0-40%), 8 patients developed portal hypertension, 5 liver failure without portal hypertension and 14 heart failure. With 62 patients having died, the series' median survival was 59 months (95% CI: 41-75).
Conclusion: IM is usually diagnosed in the old age. From the histologic point of view, a predominance of the cellular phase is observed at disease presentation. In recent years an increased proportion of patients asymptomatic at diagnosis is observed.