The haematological and histological findings in 18 patients with clinical features resembling those of myelofibrosis.

Abstract

Summary. The presentation and haematological abnormalities in 18 patients with splenic and hepatic enlargement and a leukaemoid or leucoerythroblastic blood picture have been reviewed. The clinical features in each case were consistent with a diagnosis of myelofibrosis. Histological examination of the bone marrow showed myeloid proliferation of various types for which no underlying cause was apparent. On the basis of the bone marrow histology, it was possible to divide the 18 patients in this study into two groups.The first group of four patients presented with a splenomegaly and a marked leucocytosis. Bone marrow aspirate and biopsy specimens showed marked granulocytic proliferation akin to chronic myeloid leukaemia, from which these cases were separated by the findings of a normal or raised leucocyte alkaline phosphatase score. Other distinguishing features these patients had in common were that they were all elderly and their illness appeared to follow a prolonged course, with little need of active treatment.The second larger group of 14 patients were less uniform. The histological and haematological appearances were variable. Excess bone marrow reticulin was present in each case, and marrow fibrosis was noted in eight. Prominent aggregations of large primitive stem cells were a histological feature in all 14 instances. Correlation between the clinical, haematological and histological features was poor and in particular the marrow aspirate gave little indication of the marrow morphology as found in the bone marrow sections.