Spongy Lymphoid Myelofibrosis as a Predictor of Hairy Cell Leukaemia or a Variant of Hairy Cell Leukaemia without Hairy Cells?

8 patients with clinical and haematological features suggestive of hairy cell leukaemia are described. During their initial illness morphologic and cytochemical evidence of hairy cell leukaemia were lacking in all but 2 patients. A common highly characteristic histopathologic finding was reticulin fibrosis in the bone marrow, present in all patients at first presentation. The term spongy lymphoid myelofibrosis is proposed for such cases, which may represent a variant type of hairy cell leukaemia or an early stage of the disease.