CD19 and lymphoma: It is important to note that cases of acute myeloid leukemia may express B cell markers, including CD19, cytoplasmic CD79a, and PAX5, particularly in acute myeloid leukemia with t(8;21)(q22;q22.1) [5], and cases of T-lymphoblastic leukemia/lymphoma may express CD10 and low-level CD79a (see below) [6].