What is the associated congenital anomaly?
Dysgenesis of the corpus callosum.
What are the two types of pericallosal lipoma, and which is this?
Curvilinear and tubonodular. This is an example of the latter.
Selected images from an MRI of the brain demonstrate dysgenesis of the corpus callosum with an inter-hemispheric fatty mass entering the lateral ventricles which have a viking helmet or moose head configuration. The anterior cerebral artery and branches can be seen coursing through the superior aspect of the mass.