Spontaneous Resolution of Symptomatic Synovial Cysts of the Lumbar Spine: A Comprehensive Review with Two Illustrative Cases

Although lumbar synovial cysts (LSCs) are frequently described in the literature, they are a relatively uncommon cause of low back and radicular leg pain. Furthermore, their spontaneous resolution is an even rarer event. The standard treatment of the lumbar synovial cyst is surgical excision. Spontaneous resolution in the literature is a sporadic event. In our experience, we have had two cases where the lumbar synovial cyst disappeared spontaneously. To date, only nine cases of spontaneous resolution of synovial cysts have been documented in the literature. In this discussion, we highlight a pathology that typically suggests surgical intervention, yet conservative treatment can be a viable alternative. We present two cases of large synovial cysts that were initially scheduled for surgery but ultimately resolved spontaneously without any treatment. While the spontaneous resolution of lumbar synovial cysts is extremely rare, conservative strategies are an option that should not be overlooked. Our cases contribute to the growing body of evidence on the spontaneous regression of symptomatic LSC, potentially enhancing the understanding of the disease's natural progression in the future.