Pudendal neuralgia caused by a sacral perineural Tarlov cyst: illustrative case

BACKGROUND: Pudendal neuralgia is one of the clinically poorly understood disease groups. The authors report a rare case of pudendal neuralgia caused by a sacral Tarlov cyst. OBSERVATIONS: A 52-year-old woman was referred to the authors' clinic with perineal pain that had been occurring for the past 6 months and worsened when she sat up. The pain could not be controlled with painkillers or nerve blocks. The diagnosis was left pudendal neuralgia, and MRI revealed a left S2 Tarlov cyst. The cyst was small, measuring 11-15 mm, making percutaneous aspiration difficult, so direct surgery was chosen. The pudendal neuralgia was determined to be due to compression of the adjacent S3, and only bony decompression of the Tarlov cyst was performed. Postoperatively, the pudendal neuralgia improved, and no recurrence has been observed 6 months after surgery. LESSONS: For small Tarlov cysts within the intervertebral foramen, bony decompression alone is a useful treatment method without complications. https://thejns.org/doi/10.3171/CASE26493.