ORIGINAL ARTICLE Clinicopathological impact of CD20 expression in childhood B cell precursor acute lymphoblastic leukemia (BCP-ALL) Salah Aref 1 & Tahani Mohamed 2 & Manal Fouda 1 & Sherin Abd El-Aziz 1 & Dina Abdel Hamid 2 Received: 6 February 2017 /Accepted: 5 April 2017 /Published online: 1 May 2017 # Springer-Verlag London 2017 Abstract Recognition of BCR/ABL translocation is obliga- tory in precursor B cell precursor acute lymphoblastic leuke- mia (BCP-ALL) patients at diagnosis for categorization of patients. The risk stratification of BCP-ALL especially those negative for Philadelphia chromosome is an area of research. The prognostic impact of CD20 expression in childhood BCP- ALL remains controversial. In pediatric patients with BCP- ALL, some studies have demonstrated that CD20 overexpres- sion correlates with bad overall survival, but some others sug- gest a better outcome. This study aimed to evaluate the effi- cacy of CD20 expression as a biological marker in BCP-ALL. For 104 children with newly diagnosed BCP-ALL included in this study, CD20 expression was evaluated by flow cytometry. CD20 was positively expressed in 40 (38.5%) of cases. The CD20 positive subgroup had significantly shorter overall surviv- al and disease free survival as compared to the CD20 negative one (P = 0.018; <0.001, respectively). Combined positivity for CD20 and Philadelphia chromosome was detected in 16/ 40 of studied cases. This patient group had the poorest overall survival and the shortest disease-free survival. In conclusion, CD20 expression at diagnosis in BCP-ALL is a useful bio- marker for risk stratification and subsequently in treatment decision especially in Philadelphia negative BCP-ALL. Keywords Prognosis . Precursor B cell ALL . CD20 Introduction Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, representing one third of pediatric can- cers. Among ALL, B cell acute lymphoblastic leukemia (B- ALL) represents 80 to 85% of the childhood ALL (Ribera and Oriol 2009). In Egypt, the annual incidence is approximately four cases per 100,000 children per year in the National Cancer Institute (NCI), Cairo University (Shalaby et al. 2010; Hoelzer and Gokbuget 2000). The Philadelphia chromosome (Ph positive ) reflects a balanced reciprocal translocation between the long arms of chromo- somes 9 and 22 (t(9;22) (q34;q11.2)) involving the BCR and ABL genes. Detection of BCR/ABL gene rearrangements is mandatory in precursor B-ALL patients at diagnosis for prog- nostic stratification and treatment decision (Rowley 2000). The CD20 molecule is expressed on the surface of both immature and mature B-cells but did not expressed on the fully mature plasma cells. It is a membrane embedded non- glycosylated phosphoprotein (Chu et al. 2006). CD20 is a marker for B cell differentiation with a variable degree of expression in B cell precursor acute lymphoblastic leukemia (BCP-ALL). Its significance in this disease is of conflict results. The immunophenotyping shows a vital diag- nostic role and prognostic impact in ALL cases. The limitation for intensification chemotherapy regimen makes hope maybe in targeted treatment. The expression of CD20 was reported in the majority of mature B-ALL blast cells, and in only 30–50% of BCP-ALL blast cells. This variable expression increases the problem of the potential prognostic significance of CD20 expression in BCP-ALL patients, which has been mostly stud- ied in pediatric series and yielded conflicting results (Gökbuget and Hoelzer 2004). Studying the predictive significance of CD20 expression in BCP-ALL in children is still of conflicting results. In adults, * Salah Aref salaharef@yahoo.com 1 Hematology Unit, Clinical Pathology Department, Mansoura University, Mansoura, Egypt 2 Faculty of Science, Mansoura University, Mansoura, Egypt Comp Clin Pathol (2017) 26:943–949 DOI 10.1007/s00580-017-2469-4