Parenchymal Neurocutaneous Melanosis in Association with Intraventricular Dermoid and Dandy-Walker Variant: A Case Report

Abstract

Neurocutaneous melanosis (NCM) is a rare congenital disease that is characterized by the presence of large or multiple congenital melanocytic nevi and melanotic lesions of the central nervous system. We report here on the CT and MR imaging findings of an unusual case of NCM that was associated with intraventricular dermoid and Dandy-Walker malformation.

Congenital melanocytic nevi: Where are we now?

“…136,139,145,153,154 In addition, the Dandye Walker malformation has been described with NCM and suggests an even more worrisome prognosis. [155][156][157][158][159][160] Other CNS abnormalities have been reported, including lissencephaly and corpus callosum agenesis. 161 The leptomeningeal spread of a tumor indicates a more diffuse mesenchymal dysplasia and a poorer prognosis.…”

Neurocutaneous melanosis in association with Dandy-Walker malformation: case report and literature review

“…Hydrocephalus, the most common complication, occurs in two‐thirds of patients with symptomatic NCM and in all patients with both NCM and DWM (Table 1). It is speculated that arachnoid villi are infiltrated by melanocytes leading to cerebrospinal fluid malabsorption or an obstruction of the cisterna magna 6–9 3 .…”

“…first reported the association of NCM and DWM. One pathogenetic model of this association is that xenotopic melanocytic cells inhibit extracellular matrix formation by meningeal cells and thus lead to destabilization of the basal lamina, which in turn leads to abnormal cell migration and cerebellar malformation 6–8 . Aside from their implications in DWM, Zic 1 and other genes (eg Pax3 ) have been shown to be involved in the regulation of neural‐crest cell proliferation and differentiation 12 .…”

Symptomatic Neurocutaneous Melanosis and Dandy-Walker Malformation in an Adult

“…2,4 The majority of patients with NCM present with neurologic symptoms in the first 2 years of life. 7 In contradistinction, our patient presented with mild symptoms that progressively worsened over years rather than months. 5 Once symptomatic, patients with NCM have a poor prognosis.…”

“…3 Approximately 115 cases of NCM, mostly children, have been described in the literature. 7,8 Other than retarded psychomotor development, he was described as normal until his presentation, but he deteriorated within months after resection of a left-temporal melanocytoma. 2 The most common manifestations of NCM result from increased intracranial pressure, and include seizures, headaches, and vomiting.…”