A unique presentation of trigeminal neuralgia related to a central nervous tissue choristoma along the trigeminal nerve root: illustrative case.

Background: Trigeminal neuralgia (TNa), or tic douloureux, is characterized by severe facial pain triggered by everyday activities. Recurring and intense TNa pain results from localized demyelination within the affected nerve segment. The primary cause of TNa is typically vascular compression, with the superior cerebellar artery being the most common vessel. Tumors, multiple sclerosis, and infectious diseases such as herpes are less frequent causes of TNa.

Observations: The authors present a unique case in which TNa was caused by an aberrant mass resembling a schwannoma during surgery. However, histological examination revealed heterotopic benign central nervous neurons and myelinated axons, which could represent a choristoma in the cisternal segment of the portio major of the trigeminal nerve. Following surgery, the patient's TNa was completely resolved.

Lessons: To the best of the authors' knowledge, this is the first documented case of a central nervous tissue choristoma causing TNa and responding positively to surgical intervention, aside from one previous report that did not specifically use the term "choristoma" in identifying the lesion. This case highlights the challenges involved in diagnosing and managing a rare TNa presentation, with a particular focus on pathology findings. It underscores the potential role of surgery for patients whose condition is resistant to medical intervention. https://thejns.org/doi/10.3171/CASE24384.