Pediatric meningeal melanomatosis with the presence of atypical melanocytic cells in the cerebrospinal fluid

―A case report―

Abstract

Background : Meningeal melanomatosis is an extremely rarely encountered condition in pediatric practice. Herein, we report a case of pediatric meningeal melanomatosis in which atypical melanocytic cells were detected in the cerebrospinal fluid.

Case : A 4-year-old boy was admitted to our hospital with a history of dysstasia, vomiting and altered consciousness, and was suspected as having encephalitis. After admission, the findings of MRI suggested the possibility of leptomeningeal melanosis, and cerebrospinal fluid (CSF) cytology and brain biopsy were performed. CSF cytology showed atypical cells with intracytoplasmic melanin, and brain biopsy revealed atypical cells containing melanin proliferating under the arachnoid membrane and invading the cerebral parenchyma. Finally, the diagnosis of meningeal melanomatosis was established.

Conclusion : Meningeal melanomatosis is extremely rare. Neither the symptoms nor the imaging findings are specific, and it is often difficult to distinguish this condition from other diseases of the nervous system, like meningitis. CSF cytology has an important role in the diagnosis.