abnormal septum pellucidum morphology abnormal septum pellucidum size MPheno.ontology abnormal septum lucidum size MP:0012005 anomaly in the size of the thin, triangular, vertical membrane separating the anterior horns of the left and righ of the septum, which has strong projections to hypothalamic and midbrain regions and receives projections from the hippocampus and amygdala abnormal lateral septum size csmith 2013-06-10T16:14:10Z