phenotype affects entity B cell Abnormal B cell morphology B cells are bursal or bone marrow-derived lymphocytes whose principle function in the adaptive immune system is to make antibodies against antigens. A simple definition of B lymphocytes is a population of cells that express clonally diverse cell surface immunoglobulin (Ig) receptors recognizing specific antigenic epitopes. Over 10 B cell-specific cell surface molecules have been identified by monoclonal antibodies, including CD19, which is considered a pan-B cell and possibly follicular dendritic cell marker, and CD20, which is considered to be a marker for mature B cells. Abnormal B cells HP:0002846 A structural abnormality of B cells. Abnormality of B cells UMLS:C4021748 Abnormal lymphocyte morphology abnormal B cell morphology b cell morphology abnormal B-cell morphology