**5. Histopathology**

Gradually, the cellular elements in the thymus and lymphatic organs begin to disappear [27]. Depletion of small lymphocytes from T cell areas, reticular cell stroma protrusions, and the presence of abnormal plasma cells, often associated with extracellular plasmacytosis and hematopoiesis, are consistently seen in the lymph nodes and spleen of patients with WAS [28]. In a study of spleens obtained from WAS patients undergoing splenectomy, gradual depletion of the marginal zone involving B cells was also observed [29]. It may be possible to justify the disruption of the antibody response to selected polysaccharides and protein antigens by examining these histological abnormalities.
