PDF
ePub
Citation
Print
Abstract
The differential diagnosis of acute lymphoblastic leukemia (ALL) from other small round blue cell tumors in children is very important for proper treatment, but sometimes difficult. CD45 is expressed on almost all-human leukocytes and not expressed on other small round blue cell tumors. Moreover, CD19 is expressed on all stages of B lineage cells and loss of this antigen is very rare in precursor B-cell ALL. We report a case of ALL with atypical morphology and immunophenotype. A 6-yr-old girl presented with fever and weight loss. Many abnormal cells with variable sized, high nuclear-cytoplasmic ratio and distinct nucleoli were counted 23% in bone marrow. The results of immuno-phenotyping were negative for CD45, CD19, CD10, CD20, CD3, CD5, CD7, CD56/16, CD13, and CD33 and positive for CD22, TdT, and CD34. The immunohistochemical staining of bone marrow biopsies was positive for CD79a, CD10, TdT and CD99. The cytogenetic study showed normal karyotype but amplification of MLL (myeloid/lymphoid or mixed lineage leukemia) gene was suggestive in the fluorescent in situ hybridization. The patient received the standard chemotherapy for acute lymphoblastic leukemia and reached complete remission.
References
1. Komada Y, Zhang X L, Zhou Y W, Inaba H, Deguchi T, Azuma E, et al. Flow cytometric analysis of peripheral blood and bone marrow for tumor cells in patients with neuroblastoma. Cancer. 1998; 82:591–9.
2. Mechtersheimer G, Barth T, Ludwig R, Staudter M, Moller P. Differential expression of leukocyte differentiation antigens in small round blue cell sarcomas. Cancer. 1993; 71:237–48.
3. Ratei R, Sperling C, Karawajew L, Schott G, Schrappe M, Harbott J, et al. Immunophenotype and clinical characteristics of CD45-negative and CD45-positive childhood acute lymphoblastic leukemia. Ann Hematol. 1998; 77:107–14.
4. Paulus U, Couzens S, Jenny M, English M, Poynton C. CD45 negative acute lymphoblastic leukemia in children. Br J Haematol. 2001; 113:45.
5. Warzynski M J, Graham DM, Axtell RA, Higgins JV, Hammers YA. Flow cytometric immunophenotyping test for staging/monitoring neuroblastoma patients. Cytometry. 2002; 50:298–304.
6. Okcu MF, Wang RY, Bueso-Ramos C, Schober W, Weidner D, Andrassy R, et al. Flow cytometry and fluorescence in situ hybridization to detect residual neuroblastoma cells in bone marrow. Pediatr Blood Cancer. 2005; 45:787–95.
7. Chen YH, Tang YM, Shen HQ, Song H, Yang SL, Shi SW, et al. The expression of CD19 in 210 cases of childhood acute leukemia and its significance. Zhonghua Er Ke Za Zhi. 2004; 42:188–91.
8. Craig W, Poppema S, Little MT, Dragowska W, Lansdorp PM. CD45 isoform expression on human haemopoietic cells at different stages of development. Br J Haematol. 1994; 88:24–30.
9. Behm FG, Raimondi SC, Schell MJ, Look AT, Rivera GK, Pui CH. Lack of CD45 antigen on blast cells in childhood acute lymphoblastic leukemia is associated with chromosomal hyperdiploidy and other favorable prognostic features. Blood. 1992; 79:1011–6.
10. Caldwell CW, Patterson WP, Hakami N. CD45 expression and prognosis in acute lymphoblastic leukemia. Blood. 1993; 81:562–3.
Fig. 1.
Bone marrow findings showed many abnormal cells with highly variable sizes, a high nuclear-cytoplasmic ratio, fragile cytoplasm, and loose chromatin (A). Dysplastic changes were present in myeloid and erythroid series (B). Megakaryocytes showed dysplasia, e.g., separated nucleation (C). A biopsy showed scattered immature cells and an increased megakaryocyte count (D).
XML Download