A RARE ATYPICAL MYELOPROLIFERATIVE DISORDER-LIKE HEMOPATHY WITH MARKED DYSPLASIA, PERIPHERAL DOMINANT MYELOBLAST PROLIFERATION AND EXTRAMEDULLARY HEMATOPOIESIS WAS CONVERTED INTO TYPICAL ACUTE MYELOID-LEUKEMIAWITH AN INTERVAL OF COMPLETE HEMATOLOGICAL REMISSION

We describe a patient with leukocytosis with all the stages of neutrop hilic series, peripheral dominant myeloblast proliferation, marked dys plasia of myeloid and erythroid series, and extramedullary hematopoies is of the lymph nodes. A cytogenetic study of the bone marrow cells sh owed normal karyotype, and molecular analysis of the leukemic cells sh owed negative for BCR-ABL by RT-PCR. After chemotherapy, the patient w ent into complete remission with a normal blood and bone marrow profil e with no dysplasia. On relapse, the hematological findings showed a t ypical bone marrow dominant acute myeloid leukemia, with the leukemic cells having a chromosomal abnormality. The patient exhibited the comb ined features of myeloproliferative disorder, myelodysplastic syndrome , peripheral dominant myeloblast proliferation (so-called peripheral l eukemia) and typical acute myeloid leukemia throughout the clinical co urse. This is thought to be a rare overlapping disease involving these distinct hematological conditions that do not usually occur in the sa me patient. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved .