Spinal neurocutaneous melanosis without cutaneous nevi

Area of Science:

• Neurology
• Oncology
• Dermatology

Background:

• Neurocutaneous melanosis is a rare congenital syndrome involving central nervous system melanocytic tumors and cutaneous nevi.
• Symptomatic cases often have a poor prognosis, with malignant transformation leading to a life expectancy under one year.
• Current treatments are primarily palliative, focusing on symptom management.

Observation:

• A 29-year-old man presented with spinal symptoms including hypesthesia and spastic gait, but no cutaneous nevi.
• Spinal MRI revealed an intradural tumor at the T5 level.
• Surgical decompression and resection of a pigmented tumor were performed.

Findings:

• Histological examination revealed a low-grade pigmented tumor, diagnosed as meningeal melanocytoma with leptomeningeal melanosis.
• Crucially, this diagnosis was made in the absence of any cutaneous nevi.
• The patient experienced immediate neurologic recovery and remained recurrence-free for three years post-surgery.

Implications:

• This case suggests a possible forme fruste of neurocutaneous melanosis, presenting without the typical skin manifestations.
• Highlights the importance of considering neurocutaneous melanosis even with atypical presentations.
• Demonstrates the potential for favorable outcomes with prompt surgical management in selected cases.