Hydrocephalus associated with intraspinal tumors constitutes a well-documented occurrence. The accepted mechanisms for this association seem to be well established. On the contrary, hydrocephalus in the context of intraspinal dermoids has been rarely recognized and its pathogenetic mechanism appears to be different.
The authors report four pediatric cases of spinal dermoid tumors and dermal sinuses that developed hydrocephalus during the evolution of these congenital lesions of ectodermal origin.
In two children, the mechanism leading to the development of hydrocephalus consisted of leptomeningeal inflammation due to bacterial meningitis or to spillage of dermoid cyst contents in the cerebrospinal fluid spaces. We hypothesize that ventricular dilatation in the other two might be the result of chemical meningitis occurring during intrauterine life. Two cases developed ventriculomegaly prior to the diagnosis of their spinal cord disease.
The unusual evolution of these cases suggests that neuroimaging studies that include the spine should be performed in cases of childhood "unexplained hydrocephalus".