TEL/AML1 Fusion Transcripts in Childhood B-Lineage Acute Lymphoblastic Leukemia / 대한혈액학회지

BACKGROUND: The t(12;21)(p13;q22), which fuses the TEL gene on chromosome 12p13 and the AML1 gene on chromosome 21q22, is observed in approximately 20~25% of childhood B-lineage acute lymphoblastic leukemia (ALL) cases and is associated with a favorable outcome. A retrospective study was conducted to investigate the frequency of TEL/AML1 fusion in the patients diagnosed as childhood B-precursor ALL. METHODS: Because of the low detection rate by routine karyotypic analysis, we studied 54 children with B-lineage ALL using the fluorescence in situ hybridization (FISH) analysis. RESULTS: Results of this analysis demonstrated a 9.3% frequency of TEL/AML1 fusion, relatively lower than Japanese, Taiwanese and Caucasian children. All five patients with TEL/AML1 fusion showed CD10 positivity and predominance of male patients (4:1). Two cases of TEL/AML1 positive groups expressed the myeloid antigens, but no significance was noted (P>0.05). In TEL/AML1 positive groups, the leukemia was developed between 4 and 5 years old age (favorable age) and showed low initial leukocyte counts (<50,000/micro L). CONCLUSION: Although these findings combined with earlier reports indicate that TEL/ AML1 fusion was frequent genetic abnormality in childhood ALL, relatively low frequency in Korean patients suggested the existence of geographic or racial variations in the genotype of ALL.

Hematologic Findings of Childhood Myelodysplastic Syndrome / 대한혈액학회지

BACKGROUND: The myelodysplastic syndromes (MDS) in childhood is considered to be very rare and the nature of this disease in childhood is very different from that in adults. We analyzed the hematologic findings of childhood myelodysplastic syndrome. METHODS: The retrospective study was performed with the confirmed patients who were admitted to the Department of Pediatrics, Asan Medical Center (AMC) from June 1989 till May 1999, to analyze the hematologic findings. Sixteen children with a primary myelodysplastic syndrome (MDS) were presented to AMC during a 10 year period. RESULTS: Morphological assessment of the peripheral blood and the bone marrow showed nine patients (56%) had refractory anemia (RA), two patients (13%) had RA with excess blasts (RAEB), five patients (31%) had RAEB in transformation (RAEB-t). Five children with juvenile chronic myelogenous leukemia were diagnosed over the same period. Age distribution showed the predilection between 6~10 years and male : female ratio was 1 : 1. Inperipheralblood, pancytopenia was found in seven cases (44%) and leukocytosis in four cases (25%). The bone marrow findings showed hypercellularity in 54%, hypocellularity in 8% and variable cellularity in 15% and myelofibrosis was observed in 23%. Various dyspoietic changes of erythrocytes, leuko- cytes and platelets in peripheral blood and three cell lines in bone marrow were observed and trilineage dysplasia was observed in 62% of MDS, and 56% of RA. The four cases (25%) of RAEB and RAEB-t have transformed to acute myelogenous leukemia. CONCLUSION: In our study, the MDS in childhood seemed to be characterized by higher incidence of RA. Compared with the adult MDS, trilineage dysplasia in RA was frequently seen, but, no significant differences of dyspoietic features between adults and childhood were observed.

Significance of trilineage myelodysplasia in de novo acute myeloid leukemia / 대한임상병리학회지

BACKGROUND: The findings of dysplastic features in haemopoietic cells in de novo acute myeloid leukemia(AML) is defined as AML with trilineage myelodysplasia(AML/TMDS). These cases have been reported accounting for 10-5% of de novo AML. The rate of complete remission(CR) in AML/TMDS to conventional chemotherapy is poor and relapse occur much earlier than in patients without dysplastic features. TMDS features are also observed during remission and termed this de novo AML with myelodysplastic remission marrow(AML/MRM). Recent report described that TMDS during remission was more closely related to prognosis than dysplastic features at diagnosis. We investigated the incidence of AML/TMDS and AML/MRM and evaluated the impending role of dysplasia in prognosis. METHOD: Ninety-ive patients with de novo AML from March 1994 to December 1998 were enrolled according to the FAB classifiction. To determine AML/TMDS and AML/MRM, we used Brito-abapulle's criteria and Kazuhiro's criteria. Prognosis was aalysed by the means of disease free survival(DFS) and overall survival(OS). RESULTS: Nine(9.5%) patients had AML/TMDS and it was 7.7%, 17.2%, 50% of patients with M2, M4 and M6. CR rate was 44.4% for TMDS patients compared to 76.7% for patients without TMDS(p<0.05). AML/TMDS also showed significantly shorter DFS and OS. The incidence of AML/MRM was higher in the group of AML/TMDS(44.4%) compared to AML without TMDS(8.1%) but was not related to prognosis. CONCLUSION: We concluded that the presence of TMDS in de novo AML exerts a negative effect on the ability to achieve CR and in the prognosis. But the MRM has no significance to predict poor prognosis and early relapse.

Significance of trilineage myelodysplasia in de novo acute myeloid leukemia / 대한임상병리학회지

BACKGROUND: The findings of dysplastic features in haemopoietic cells in de novo acute myeloid leukemia(AML) is defined as AML with trilineage myelodysplasia(AML/TMDS). These cases have been reported accounting for 10-5% of de novo AML. The rate of complete remission(CR) in AML/TMDS to conventional chemotherapy is poor and relapse occur much earlier than in patients without dysplastic features. TMDS features are also observed during remission and termed this de novo AML with myelodysplastic remission marrow(AML/MRM). Recent report described that TMDS during remission was more closely related to prognosis than dysplastic features at diagnosis. We investigated the incidence of AML/TMDS and AML/MRM and evaluated the impending role of dysplasia in prognosis. METHOD: Ninety-ive patients with de novo AML from March 1994 to December 1998 were enrolled according to the FAB classifiction. To determine AML/TMDS and AML/MRM, we used Brito-abapulle's criteria and Kazuhiro's criteria. Prognosis was aalysed by the means of disease free survival(DFS) and overall survival(OS). RESULTS: Nine(9.5%) patients had AML/TMDS and it was 7.7%, 17.2%, 50% of patients with M2, M4 and M6. CR rate was 44.4% for TMDS patients compared to 76.7% for patients without TMDS(p<0.05). AML/TMDS also showed significantly shorter DFS and OS. The incidence of AML/MRM was higher in the group of AML/TMDS(44.4%) compared to AML without TMDS(8.1%) but was not related to prognosis. CONCLUSION: We concluded that the presence of TMDS in de novo AML exerts a negative effect on the ability to achieve CR and in the prognosis. But the MRM has no significance to predict poor prognosis and early relapse.

Two cases of disseminated tuberculosis associated with the myelodysplastic syndrome / 대한임상병리학회지

Tuberculosis can be superimposed on many hematologic disorders. Numerous hematologic abnormalities are also associated with tuberculosis, especially disseminated form. With this controversy, when the patient has tuberculosis and hematologic abnormalities, it is important to differentiate tuberculosis from primary hematologic disorder. Especially, most patients with tuberculosis and pancytopenia have been reported to have underlying hematologic disorder. We present two rare cases in which patients with myelodysplastic syndrome had disseminated tuberculosis involving the bone marrow.

Myelodysplastic Syndrome with Delayed Maturation of Reticulocytes: A Report of Three Cases / 대한임상병리학회지

Anemia in myelodysplastic syndrome (MDS) is accompanied by reticulocytopenia in most patients. Reticulocytosis, when present, is generally less than appropriate to the degree of anemia and rarely exceeds 10%. In this report, three patients with MDS with persistent reticulocytosis are presented. In vitro reticulocyte survival studies have suggested that the reticulocytosis was caused by delay in maturation of the reticulocytes. Anemia with reticulocytosis, mimicking hemolytic disease, may be an unusual presentation of myelodysplastic syndrome, but, we emphasize that MDS should be included in the differential diagnosis of every patient presenting with anemia and high reticulocyte count. In vitro reticulotye survival study is easy to assess and valuable to diagnose this disease entity.