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Arquivos de Neuro-Psiquiatria

Print version ISSN 0004-282X

Arq. Neuro-Psiquiatr. vol.71 no.2 São Paulo Feb. 2013

https://doi.org/10.1590/S0004-282X2013000200016 

LETTERS

 

Neurocutaneous melanosis

 

Melanose neurocutânea

 

 

Roselane Sampaio de OliveiraI; Ana Paula Rangel de CarvalhoI; Fábio NoroII; Alessandro Severo Alves de MeloIII; Ruy MonteiroIV; Rodrigo GuimarãesIV; José Alberto LandeiroV

IResident Physician in the Radiology Department at Barra D'or Hospital, Rio de Janeiro RJ, Brazil
IIRadiologist at Rede Labs D'or, Rio de Janeiro RJ, Brazil
IIIAdjunct Professor of the Department of Radiology at Universidade Federal Fluminense, Niteroi RJ, Brazil
IVNeurosurgeon at Rede Labs D'or, Rio de Janeiro RJ, Brazil
VAdjunct Professor of the Department of Neurosurgery at Universidade Federal Fluminense, Niteroi RJ, Brazil

Correspondence

 

 

Neurocutaneous melanosis (NCM) is a rare phakomatosis that was first observed in 1861, in a 14-year-old girl born with a congenital nevus and suffering from mental retardation1. The pathogenesis of NCM is believed to result from an error in the morphogenesis of the neuroectoderm during embryogenesis1,2.

In this paper, we report a case of this phakomatosis, describe, and discuss the findings from cranial computed tomography (CT) scan and magnetic resonance imaging (MRI).

 

CASE DESCRIPTION

Our patient was a 29-year-old woman with a four-month history of sporadic seizures and a giant congenital melanocytic nevus on the torso (Fig 1A).

 

 

CT scan and MRI (Fig 1B and 1C) of the central nervous system (CNS) showed several lesions, which were later biopsied (Fig 1D). Histopathological analysis revealed a melanoma (Fig 1E), and the patient was then subjected to complementary examinations in order to detect the primary lesion, but without success.

The patient suffered brain death 21 days after hospital admission.

 

DISCUSSION

The diagnostic criteria for NCM were described by Fox and later reviewed by Kadonaga and Frieden3. They include the following:

· giant congenital nevus (usually larger than 20 cm in adults and between 6 to 9 cm in children) or multiple congenital nevi (more than three) in association with meningeal melanosis or CNS melanoma;

· absence of cutaneous melanoma, except in cases of histologically benign meningeal lesions;

· absence of meningeal melanoma, except in cases of benign dermatological lesions.

The symptoms of NCM include seizures, neurological focal deficit and psychiatric disorders1,4. The CNS may be compromised through parenchymatous or leptomeningeal lesions, melanosis (aggregation of benign melanocytic cells) or melanomas1,4.

The lesions shown on CT scans may be isodense or hyperdense. Melanomas (parenchymal or leptomeningeal form) and leptomeningeal melanosis usually show enhancement after contrast administration4.

On MRI, T1-weighted sequences show hyperintense parenchymal lesions, while leptomeningeal lesions may be isointense or hyperintense. After contrast administration, parenchymal melanosis does not commonly show enhancement in T1, while leptomeningeal lesions (melanosis and melanoma) show diffuse enhancement1,4.

On T2-weighted sequences, lesions usually present a low or intermediate signal. It should be noted that lesions present high signal intensity in FLAIR (fluid-attenuated inversion recovery)1,4.

It is well known that the signs that indicate melanoma instead of benign melanocytic lesions are mass effect, edema, hemorrhage and necrosis1,4.

Leptomeningeal lesions associated with edema were observed at CT scan and MRI in our patient, indicating possible melanoma, as later confirmed by the histopathological analysis. Even though the image characteristics may indicate benign melanocytic lesions or melanoma, the prognosis is better correlated with the onset of neurological symptoms4.

The treatment is palliative and includes systemic and intrathecal chemotherapy and radiotherapy, as well as ventriculoperitoneal shunt (with filter) in cases of hydrocephaly. In addition, regardless of the treatment, the prognosis is bad4.

In conclusion, although it is a rare entity, NCM should be investigated among patients presenting central neurological symptoms associated with congenital melanocytic nevus.

 

References

1. Smith AL, Rushing EJ, Smirniotopoulos JG. Pigmented lesions of de central nervous system: radiologic-pathologic correlation. Radiographics 2009;29:1503-1524.         [ Links ]

2. Barkovich AJ. Pediatric neuroimaging. Fourth edition. Philadelphia: Lippincott Williams & Wilkins, 2005. p. 487-488.         [ Links ]

3. Kadonaga JN, Frieden IJ: Neurocutaneous melanosis: definition and review of the literature. J Am Acad Dermatol 1991;24:747-755.         [ Links ]

4. Osborn AG, Blaser SI, Salzman KL, Katzman GL, Provenzale J, Castillo M. Diagnostic imaging: Brain. Salt Lake City: Amirsys, 2004:I-1-116-I-1-119.         [ Links ]

 

 

Correspondence:
Roselane Sampaio de Oliveira
Avenida Ayrton Senna 2541, Barra da Tijuca
22775-002 Rio de Janeiro RJ - Brazil
E-mail: roselanesam@yahoo.com.br

Received 14 December 2011;
Received in final form 16 July 2012;
Accepted 23 July 2012
Conflict of interest: There is no conflict of interest to declare.

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