Neurocutaneous melanocytosis with manifestation in adulthood

A 20-year-old patient was presented with subacute onset of headache, nausea and vomiting. Testing of nasal/oropharyngeal swabs indicated the presence of SARS-CoV-2 RNA, and later the antibodies to this virus were found. The treatment in the hospital for Coronavirus 19 Disease (COVID-19) provided only temporary relief, and the patient then was referred to the Regional Stroke Center (RSC) to exclude a subarachnoid hemorrhage. RSC neurologists drew attention to multiple skin nevi in the patient. Brain MRI demonstrated abnormal T1 hyperintensity in the brain leptomeninges, with leptomeningeal contrast enhancement as well as hyperintensity in amygdala regions on T1 weighted images, bilaterally. The anomaly of the Dandy-Walker malformation complex was also revealed. Cerebrospinal fluid (CSF) analysis showed elevated protein (0.52 g/L), low lymphocytosis (lymphocytes, 6 in mm3), and decreased glucose (1.8 mmol/L). Neurocutaneous melanocytosis (NCM) was diagnosed, which neurological manifestation was probably triggered by COVID-19. The patient’s vision gradually progressively worsened. In 2.5 months after the clinical manifestation of NCM, fundoscopy revealed optic discs atrophy (despite the absence of previous edema), and repeated CSF analysis showed atypical cells with characteristics corresponding to melanoma. Malignant transformation of cerebral melanocytosis was suspected, and the patient was referred to an oncological dispensary for further therapy. In the presented literature review, special attention is paid to the issues of neuroimaging, cytological and immunocytochemical diagnostics of NCM.