Abstract
A case of primary myelofibrosis involving lymph node and with a novel cytogenetic abnormality [del (18) (p11.2-3)] is reported. The abnormalities are identical among specimens from the lymph node, peripheral blood, and bone marrow that were analyzed years apart. Additionally, we show that the infiltrate by dysplastic megakaryocytes in the lymph node morphologically mimics a metastatic mesenchymal neoplasm, even when the clinical history myelofibrosis was known.