TY - CHAP M1 - Book, Section TI - Precursor Lymphoblastic Lymphoma A1 - MA, Lichtman A1 - MS, Shafer A1 - RE, Felgar A1 - N, Wang Y1 - 2017 N1 - T2 - Lichtman's Atlas of Hematology 2016 AB - Graphic Jump LocationView Full Size||Download Slide (.ppt)VII.B.001Precursor lymphoblastic lymphoma, T-cell type. Precursor lymphoblastic lymphoma, T-cell type. (A) Marrow section. Replaced with lymphoblasts with high nuclear:cytoplasmic ratio, small nucleoli, and irregular nuclear outlines. (B) Marrow touch preparation showing typical lymphoblast cytology: high nuclear:cytoplasmic ratio, inconspicuous nucleoli, irregular nuclear outlines. A few vacuoles are present in this case. (C) Marrow biopsy section with positive immunostain for terminal deoxynucleotidyl transferase (TdT) indicated by reddish brown nuclear stain. Some cases of very immature myeloid leukemias (AML-MO) may have a similar cytologic appearance and will be myeloperoxidase-negative on cytochemical staining. Precursor T-cell and precursor B-cell neoplasms can have similar morphologic features, although precursor T-cell cases are more likely to have convoluted or lobulated nuclei. Either one can express TdT, which indicates an immature lymphoid origin. Precursor Bcell neoplasms are defined by expression of surface CD19 and/or CD79a, CD10, and cytoplasmic CD22, with lack of surface kappa or lambda immunoglobulin light chain expression. Precursor T-cell neoplasms are defined by lack of surface CD3 expression, cytoplasmic co-expression of CD3, lack of surface T-cell receptors, and often show either dual lack of CD4 and CD8 or dual co-expression of CD4 and CD8, phenotypes that mimic the stages of immature thymocytes. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1138038004 ER -