Abnormal corpus callosum morphology Thin corpus callosum 2021-04-07T16:39:13Z Small corpus callosum Thinning of the corpus callosum An abnormally thin corpus callous, due to atrophy, hypoplasia or agenesis. This term is intended to be used in situations where it is not known if thinning of the corpus callosum (for instance, as visualized by magnetic resonance tomography) is due to abnormal development (e.g. a leukodystrophy) or atrophy following normal development (e.g. neurodegeneration).