Flow cytometry histograms of bone marrow from a patient with relapse of precursor B-ALL illustrating multiple antigenic aberrancies.

The lymphoblasts (red) exhibit an abnormal spectrum of expression of CD22 and overexpression of CD10 relative to the normal hematogone population (violet). They are uniformly CD34-positive and -negative for CD20 and CD45. The lymphoblasts express the myeloid-associated antigens CD36 and CD33 and underexpress CD38. Red indicates neoplastic lymphoblasts; violet, hematogones; and blue, mature B lymphocytes.