abnormal thymus lobule morphology abnormal thymus corticomedullary boundary morphology MP:0009543 MPheno.ontology abnormal thymic corticomedullary boundary morphology abnormal thymus CMZ morphology abnormal thymus cortico-medullary boundary abnormal thymus cortico-medullary junction abnormal thymus cortico-medullary zone abnormal thymus corticomedullary zone morphology any structural anomaly of the dense region demarcating the thymus medulla from the surrounding cortex that is characterized by numerous blood vessels (predominantly arterioles) with some perivascular connective tissue, mature and immature T lymphocytes, dendritic cells, variable numbers of perivascular B-lymphocytes and plasma cells; site of entry of bone marrow stem cells and exit of mature, functional T cells