Primary Diffuse Leptomeningeal Melanocytosis: A Rare and Challenging Diagnosis

Abstract

Primary melanocytic neoplasms of the central nervous system are rare entities and can present in different clinical forms with mild and non-specific symptoms (such as headache and tinnitus) to severe and limiting symptoms (focal deficits and intracranial hypertension), mimicking the most diverse pathologies. In addition to the peculiar changes in imaging tests, diagnosis is always a challenge given the multitude of possible differential diagnoses, including aseptic meningitis. Given this, we bring here the case of a 59-year-old patient who attended care due to headache and vertigo followed by involvement of the cranial nerves and spinal cord, corroborated by physical examination and imaging study suggesting diffuse involvement of the meninges, which was subsequently confirmed by anatomopathological examination as a primary melanocytic neoplasm of the central nervous system but ended up dying due to complications resulting from late diagnosis. The objective of this work is to raise awareness about the possibility of this pathology as a differential diagnosis in these cases where there are often frustrating clinical manifestations but with changes in imaging tests, to enable an early diagnosis and consequently the possibility of a better therapeutic result, in addition to a brief review of the propaedeutic findings of this pathology.