S-100-negative, GNA11 mutation-positive intramedullary meningeal melanocytoma of the thoracic spine: A radiographic challenge and histologic anomaly.

Background Intramedullary melanocytomas are exceedingly rare and their management is largely based on case reports and small clinical series. They have characteristic imaging and histologic findings that can aid in their diagnosis. Genetic testing may be required for definitive diagnosis and management guidance in ambiguous cases. Case description We present the case of a thoracic intramedullary meningeal melanocytoma in a patient unable to undergo an MRI. Conclusion This is the first reported S-100-negative case with genetic testing to support the diagnosis of a rare intramedullary melanocytoma.