Leptomeningeal melanomatosis: a case report

INTRODUCTION: Leptomeningeal melanomatosis is a rare neoplasm of the central nervous system that develops as a result of non-metastatic invasion by malignant melanocytic cells. The disease poses significant diagnostic challenges due to a wide range of clinical manifestations, lack of specific laboratory markers, and absence of definitive neuroimaging findings. Particular attention should be given to differentiating leptomeningeal melanomatosis from other central nervous system disorders, infectious and neoplastic diseases of different origin, and metastases, given the similarities in clinical presentation and pathomorphological features. CASE DESCRIPTION: A 20-year-old patient was diagnosed with leptomeningeal melanomatosis. Despite the absence of detectable melanoma in biopsy (surgical) specimens during antemortem pathological examination, the scientific data indicates that this does not preclude an aggressive clinical course following symptom onset. The report presents the patient’s clinical history and disease progression over one year, culminating in a fatal outcome. CONCLUSION: This case illustrates the diagnostic and therapeutic difficulties associated with rare central nervous system disorders, particularly when the diagnosis remains unclear over a long period. The scarcity of reliable data on leptomeningeal melanomatosis, the rapid disease progression, and its high mortality make timely diagnosis extremely challenging.