Brain Atrophy Associated with Primary Diffuse Meningeal Melanomatosis.

Abstract

Primary meningeal melanomatosis is a rare leptomeningeal tumor, and the diagnosis is challenging due to nonspecific clinical symptoms and radiologic findings. A 21-year-old man presented with recurrent seizure and impaired memory. Cranial magnetic resonance imaging showed obvious brain atrophy with bilateral extensive meningeal enhancement in the supratentorial region. Diffusion-weighted imaging and fluid-attenuated inversion recovery showed slightly hyperintensive signals in the cortex. Microscopic examination revealed invasion of pigment into the Virchow-Robin space and cortex. Immunohistochemical examination of biopsy samples showed that cells were immunopositive for HMB45 and S-100 and immunonegative for melan-A with a Ki-67-positive percentage of 3%. No obvious atypia or nuclear mitosis was observed. Pathohistologic results of biopsied meninges confirmed the diagnosis of diffuse meningeal melanomatosis. The disease was aggravated with the occurrence of brain atrophy, recurrent seizure, and declined higher cortical function. This case report illustrates that brain atrophy in meningeal melanomatosis is associated with a progressive decline of higher cortical function.