The immunophenotype of pre-TALL/LBL revisited
Robert E. Lewis, Julius M. Cruse⁎, Catherine M. Sanders, Rachel N. Webb, Benjamin F. Tillman,
Kevin L. Beason, John Lam, Jonathan Koehler
Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, Mississippi 39216, USA
Available online 14 August 2006
Flow cytometric analysis of cluster of differentiation (CD) markers in abnormal lymphocyte populations is crucial in the diagnosis of precursor
T cell acute lymphoblastic leukemia (T-ALL)/lymphoblastic lymphoma (LBL). The World Health Organization (WHO) suggested
immunophenotype for pre-T ALL/LBL typically includes the expression of TdT, cCD3, and CD7, while CD2, CD3, CD4, CD5, CD8, and
CD10 are variably expressed. The myeloid antigens CD13 and CD33 are usually positive, whereas CD117 and cCD79a are infrequently
expressed. Furthermore, there is frequent dual expression of CD4 and CD8. In the present investigation, 19 cases of pre-TALL/LBL were analyzed
for selected CD marker expression. Fifteen of 19 cases studied were evaluated for TdT, cCD3, and cCD79a expression. Eleven (73.3%) positively
expressed TdT, 15 (100%) positively expressed cCD3, and 9 (60%) positively expressed cCD79a. Of the 17 cases analyzed for CD7, CD5, and
CD10 expression, CD7 and CD5 were positive in all 17 (100%) cases, whereas CD10 was positive in 8 (47.1%) cases. Of the 18 cases evaluated
for CD2, CD3, CD4, CD8, and dual expression of CD4 and CD8, CD2 was expressed in 14 (77.8%), while CD3 was expressed in 7 (38.9%)
cases. CD4 was positive in 11 (61.1%), and CD8 was expressed in 9 (50%). Dual expression of CD4 and CD8 occurred in only 4 (22.2%) of the
cases. Of the 16 analyzed for CD13, CD33, and CD117, only 1 case (6.3%) expressed CD13, while 2 (12.5%) cases expressed CD33 and CD117.
Thus, these data point to the need for a more extensive study to reevaluate the current WHO defined immunophenotype used in the diagnosis of
© 2006 Elsevier Inc. All rights reserved.
Keywords: Pre-TALL; Precursor T cell acute lymphoblastic leukemia; TdT; CD3; CD5
Precursor T cell acute lymphoblastic leukemia (T-ALL)/
lymphoblastic lymphoma (T-LBL) is a disease involving the
presence of neoplastic Tcell lymphoblasts in both the blood and
the bone marrow. When there is extensive involvement in both
the bone marrow and the blood, the preferred term is leukemia.
However, if a mass lesion is present with minimal blood and
bone marrow involvement, the appropriate term is lymphoma
(Jaffe et al., 2001). As cells mature, they undergo antigenic
transformation or the gain and loss of specific cluster of diffe-
rentiation (CD) markers. In addition, cells also undergo
antigenic transformation as they become malignant. The CD
markers are analyzed using flow cytometry in order to dis-
tinguish different types of leukemias and lymphomas.
Normal T lymphoblasts usually express TdT, CD2, CD5,
CD7, and lack CD3 while cCD3 is typically expressed. CD4
and CD8 are usually coexpressed (Cruse et al., 2004). The
World Health Organization (WHO) suggested immunopheno-
type for pre-T ALL/LBL typically includes the expression of
TdT, cCD3, and CD7, while CD2, CD3, CD4, CD5, CD8, and
CD10 are variably expressed. The myeloid antigens CD13 and
CD33 are usually positive, whereas CD117 and cCD79a are
infrequently expressed. Furthermore, there is frequent dual
expression of CD4 and CD8 (Jaffe et al., 2001).
Materials and methods
Nineteen cases of precursor Tcell acute lymphoblastic leukemia/lymphoma
were diagnosed based on immunophenotype, clinical assessment, and mor-
phology over the course of four years in the Department of Pathology at the
University of Mississippi Medical Center in Jackson. Immunophenotyping was
performed by analysis of peripheral blood samples collected in EDTA, bone
marrow aspirates, and lymph node cell preparations by flow cytometry (Epics
XL and FC500, Beckman and Coulter, Miami, FL) using standard techniques.
Experimental and Molecular Pathology 81 (2006) 162–165
⁎Corresponding author. Fax: +1 601 984 1835.
E-mail address: email@example.com (J.M. Cruse).
0014-4800/$ - see front matter © 2006 Elsevier Inc. All rights reserved.