Polycystic brain (cerebrum polycystica vera) associated with ectodermal dysplasia: a new neurocutaneous syndrome.

This paper presents a unique case of true polycystic brain in which multiple cysts of curvilinear, round, oval, or layered configuration occurred. These apparently represented extremely dilated Virchow-Robin spaces: the perivascular spaces lined by ependymal/leptomeningeal cells. Irregular retinal pigment epithelium was also evident. In addition, the patient showed ectodermal dysplasia manifesting as thin hair, dystrophic nails, and dental abnormalities. A common ectodermal origin for the brain cysts and the ectodermal changes is proposed, as it is known that the central nervous system (including the ependymal/leptomeningeal cells and the retinal cells), the epidermis (including hair and nails), and the enamel of the teeth have the same origin-the embryonic ectoderm. This association appears to be a new, distinct neurocutaneous syndrome.