Symptomatic Neurocutaneous Melanosis and Dandy-Walker Malformation in an Adult

Dandy-Walker Malformation Associated with Neurocutaneous Melanosis

“…A few more than 100 cases have been published so far [1][2][3][4][5]10,11,[13][14][15][16]18,19) . This disease is characterized by one or multiple large congenital melanocytic nevi and diffuse or nodular leptomeningeal involvement of melanocytes.…”

“…Whether the ventricular outlet is obstructed or not, the dysgenesis of the cerebellum and fourth ventricle may result in the gradual accumulation of CSF in the posterior fossa, but still allow absorption in a critical equilibrium because of the relatively high-pressure gradient between the CSF pathway and the venous compartment. The physiological increase in systemic blood pressure after birth results in a decreased pressure gradient and a disruption of the absorption of CSF, leading to hydrocephalus [1][2][3][4][5]7,[10][11][12][13][14]18,19) . At least 100 cases of neurocutaneous melanosis have been reported; in 15 cases, there were associations between DandyWalker malformation and neurocutaneous melanosis [1][2][3][4][10][11][12][13][14][15][16]18,19) .…”

“…Neurocutaneous melanosis is a rare dysmorphogenesis that is associated with single and multiple giant pigmented cutaneous nevi and the involvement of benign and/or malignant melanocytic tumors of the leptomeninges. After the first description by Rokitansky 17) , around 100 cases of neurocutaneous melanosis have been reported in the literature [1][2][3]5,10,11,[13][14][15][16]18,19) . Eight to 10% of these were associated with Dandy-Walker malformation, indicating a common origin of these developmental abnormalities [1][2][3]7,10,11,13,14,18,19) .…”

Neurocutaneous Melanosis

“…Such leptomeningeal abnormalities might affect the proper development of the fourth ventricle and the cerebellum, resulting in an increased association of DWM with NCM. 8 Of the approximately 115 cases of NCM reported, in at least 15 cases, there was an association with DWM. The association of Dandy-Walker malformation with DWM seems to have an extremely poor prognosis.…”

“…In a series of 71 cases, 5 mortality occurred in 55 patients (77%), with a median survival time of 6.5 months after symptom onset and a median age at death of 4.5 years. 8 The macroscopic histological features of NCM have been described as thickening of the leptomeninges by infiltrative tumour cells with predilection for the basal surface of the brain as well as the rostral portion of the brain stem. Lesions over the convexity, although infrequent, can associate with invasion of the brain parenchyma.…”