Primary CNS Melanoma of Meckel's Cave: A Rare Case with Literature Review.

Meckel's cave is a dural recess in the posteromedial portion of the middle cranial fossa, serving as a conduit for the trigeminal nerve and hosting various pathologies. The radiological diagnosis of Meckel's cave pathologies is often challenging, especially when they are atypical and rarely encountered. Here, we discuss the case of a 41-year-old woman who presented with right hemifacial pain, numbness, and binocular diplopia. Imaging features suggested a T2 hypointense, T1 hyperintense, and nonenhancing mass in the right Meckel's cave. Intraoperatively, an extra-axial black mass was observed, suggestive of melanoma, which was radically excised. Further postoperative workup and biopsy revealed it was a primary central nervous system (CNS) malignant melanoma, an exceedingly rare condition. Due to the rarity of the disease, a consensus regarding treatment regimens is lacking. This case report underscores the significance of considering uncommon diagnoses when faced with unusual radiological findings and emphasizes the importance of aggressive surgical resection and the evolving landscape of adjuvant treatments for primary CNS melanomas.