Tirado Carlos A, Reyes Andrew, Yeh Wilson, Yee Justin, King Joy, Kane Javier, Koss William
The International Circle of Genetics Studies, Los Angeles, California.
Department of Pathology, Baylor Scott and White Health, Temple, Texas.
Proc (Bayl Univ Med Cent). 2021 Jan 19;34(2):302-304. doi: 10.1080/08998280.2020.1864700.
Ring chromosomes are uncommon in hematological diseases. Here we present the case of a 13-year-old girl with leukocytosis, anemia, and lymphadenopathy. Flow cytometry analysis revealed a predominant precursor T lymphoid population expressing CD7, CD5, CD2, and cytoplasmic CD3 with partial expression of CD33, CD34, CD117, and CD11c; TdT was positive, and myeloperoxidase was negative. The bone marrow aspirate showed markedly increased blasts that were positive for CD3, CD7, CD34, TdT, and myeloperoxidase (rare positivity) by immunohistochemistry stain, consistent with T-cell acute lymphoblastic leukemia (T-ALL) extensively involving a hypercellular marrow for age. The karyotype showed a ring 7 in 12 of the 21 metaphase cells examined and deletions of the subtelomeric regions on chromosome 7. Deletions in the short arm of chromosome 7 and the long arm of chromosome 7 are present in 2% to 4% of pediatric T-ALL cases. Ring chromosome 7 is typically seen in myeloid malignancies, including acute myeloid leukemia.
环形染色体在血液系统疾病中并不常见。在此，我们报告一例13岁患有白细胞增多、贫血和淋巴结病的女孩。流式细胞术分析显示，主要为前体T淋巴细胞群，表达CD7、CD5、CD2和胞质CD3，部分表达CD33、CD34、CD117和CD11c；末端脱氧核苷酸转移酶（TdT）阳性，髓过氧化物酶阴性。骨髓穿刺显示原始细胞明显增多，免疫组化染色显示CD3、CD7、CD34、TdT和髓过氧化物酶（罕见阳性）阳性，符合T细胞急性淋巴细胞白血病（T-ALL），广泛累及该年龄组的细胞增多的骨髓。核型分析显示，在检测的21个中期细胞中有12个出现环形7号染色体，以及7号染色体亚端粒区域的缺失。7号染色体短臂和长臂的缺失存在于2%至4%的儿童T-ALL病例中。环形7号染色体通常见于髓系恶性肿瘤，包括急性髓系白血病。
