abnormal spleen white pulp morphology abnormal spleen marginal zone morphology MP:0002362 MPheno.ontology Note that there is no consensus in the literature about which compartments constitute the white pulp or the ramifications of the microvasculature. In addition, notable differences exist between humans and rodents. In this ontology, the marginal zone has been included as part of the white pulp. abnormal splenic marginal zone morphology any structural anomaly of the zone between the red and white pulp of the spleen containing numerous macrophages and lymphocytes, and a rich plexus of sinusoids supplied by white pulp arterioles carrying blood-borne antigens