Light and electron microscopic studies of megakaryocytes in bone marrow from 14 cases of Korean epidemic hemorrhagic fever were made, together with clinical manifestations, laboratory findings, and changes in other marrow elements. The number of megakaryocytes increased in various degree from patient to patient, with a shift to the left of maturation gradation. Cytoplasms were markedly smaller but granularity was fairly good. The most constant finding was marked decrease or complete absence of platelet formation at the periphery of the cytoplasm. Ultrastructurally, there was a marked decrease of the cisternal system in the cytoplasm and lack of cleavage line. No virus particles or active degenerative process was noted. These changes of the megakaryocytes are similar to those reported in idiopathic thrombocytopenic purpura, indicating that megakaryocytic changes in Korean epidemic hemorrhagic fever are likely secondary to thrombocytopenia which was caused by other Mechanism.
Adult ; Aged ; Bone Marrow/pathology ; Female ; Hemorrhagic Fever with Renal Syndrome/pathology* ; Human ; Male ; Megakaryocytes/ultrastructure* ; Middle Age

The purpose of study was to investigate the ultrastructural features of leukemic megakarocyte (LMK) in patients with acute megakaryocytic leukemia (M(7)). Analyzing the ultrastructure characteristics of LMK and positive ratio of platelet peroxides (PPO) in 11 patients with M(7) were analyzed on basis of transmission electron microscopic observation retrospectively. The results showed that the diameter of LMK in 7 out of 11 cases was less than 20 microm, in 2 cases of them, the LMK diameter was from 10 to 15 microm and their PPO positive ratio was more than 50%, most LMK displayed regular shape, less protrusions, irregular nucleus, high nuclear/cytoplasm ratio, tiny granules, undeveloped demarcation membrane system (DMS) and irregular tubules in cytoplasm; in 5 out of those 7 cases the diameter of LMK was about 20 microm, PPO positive cell count was from 8% to 22%, most showing round or horseshoe nuclei, more or less heterochromatin, no DMS and granules were found in LMK in 3 cases and 2 cases occasionally. In other 5 out of 11 cases, the diameter of LMK was from 20 to 40 microm and PPO positive ratio was from 16% to 80%, in which smaller LMKs were similar to those in former cases in shape, and the larger LMK had irregular protrusions, varied nuclear/cytoplasm ratio, more heterochromatin, prominent nucleolus, some of them contained developed DMS, tubules and alpha-granules. It is concluded that most patients with M(7) are predominant of LMK in stage-I and minority contained LMK in II or III stage simultaneously. The differentiation degrees of LMK are different in individual and various cases.
Adult ; Blood Platelets ; enzymology ; Child, Preschool ; Female ; Humans ; Infant ; Leukemia, Megakaryoblastic, Acute ; pathology ; Male ; Megakaryocytes ; ultrastructure ; Middle Aged ; Peroxidase ; blood ; Retrospective Studies ; Young Adult

This study was aimed to investigate the clinical, pathological and biological features of a special case of chronic myeloid leukemia (CML) with marked thrombocythemic onset. The morphological changes of cells were analyzed by using bone marrow smear and biopsy; Ph chromosome, a specific marker of CML, was assayed by conventional chromosomal analysis and fluorescence in situ hybridization, bcr/abl fusion gene was detected by reverse transcription-polymerase chain reaction. The results indicated that CML mimicked essential thrombocythemia (ET) at presentation was relatively rare and might be misdiagnosed as ET, bone marrow smear and biopsy revealed, marked thrombocytosis and moderate leukocytosis; RT-PCR, FISH and conventional chromosomal analysis demonstrated the existence of Ph chromosome and bcr/abl fusion gene. This special CML could progress into accelerated phase or blast crisis. The megakaryocytes in Ph+ ET were smaller than normal ones and had typically hypolobulated round nuclei. Patients diagnosed as Ph+ ET might progress into CML and showed a high tendency to myelofibrosis and blastic transformation. It is concluded that the value of routine cytogenetical and molecular biological analysis in diagnosis for potential CML cases, which mimicked ET as in this presentation, is very distinctive, and the importance is magnified by the recent availability of imatinib, a specific inhibitor of the bcr/abl tyrosine kinase produced by the Philadelphia chromosome. Every case of "ET" should be tested for the Philadelphia chromosome and bcr/abl transcript.
Adult ; Diagnosis, Differential ; Female ; Fusion Proteins, bcr-abl ; genetics ; Gene Rearrangement ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; complications ; diagnosis ; genetics ; Megakaryocytes ; pathology ; ultrastructure ; Philadelphia Chromosome ; Reverse Transcriptase Polymerase Chain Reaction ; Thrombocythemia, Essential ; diagnosis