Meningioangiomatosis in a second trimester fetus.

We describe to our knowledge the first case of meningioangiomatosis identified in a second trimester fetus. A 30-year-old pregnant woman was attended at our hospital for a second-trimester ultrasound screening scan. With a diagnosis of partial agenesis of the corpus callosum, the parents requested termination of the pregnancy. At autopsy, frontal serial sections of the fetal brain disclosed a short corpus callosum that lacked the posterior splenium, confirming the sonographic diagnosis. At close inspection, a slight bilateral hardening of both medial aspects of the frontal lobes and anterior genu of the corpus callosum was found associated with meningeal adhesion between both frontal lobes. Microscopically, cerebral cortex and corpus callosum were permeated by intersecting bundles of spindle cells with eosinophilic cytoplasm and bland, round nuclei, with a fibroblast or meningothelial-like appearance surrounding abundant blood vessels, consistent with the diagnosis of meningioangiomatosis. According to this finding, meningioangiomatosis must be included in the differential diagnosis of meningocortical fetal lesions.