Transition of a herniated lumbar disc to lumbar discal cyst: A case report

Evaluation and Treatment of Lumbar Spine Extradural Cysts: A Narrative Review

The main objective was to describe the different types and characteristics of lumbar spine extradural cysts and their optimal treatment options with a focus on endoscopic technique. We searched Pubmed, EMBASE, Medline, and Google Scholar for articles published between 1967 and 2020 using the keywords "Spinal Cyst," "Extradural Cyst," and "Lumbar Cyst." The various anatomical and histological types of the extradural cysts with their presentations, etiologies, imaging, and optimal treatment with a focus on endoscopic techniques were reviewed from the articles. Lumbar spinal cysts are relatively rare pathologies that might cause radicular symptoms similar to lumbar disc herniation. Spinal extradural cysts are classified either histologically based on the cyst lining tissues (synovial cysts or non-synovial, ganglion cysts) or anatomically based on the structure of origin (epidural cysts, ligamentum flavum cysts, discal cysts, post-discectomy pseudocysts, posterior longitudinal ligament cysts, facet cysts). Surgical excision is the recommended treatment of symptomatic cysts with endoscopic techniques being a viable option. Extradural lumbar cysts can be identified based on their histological structure or depending on their structure of origin. Regardless of their classification, they could all give similar clinical findings, and the optimal treatment would be surgical excision with endoscopic technique being a viable option with a satisfactory outcome.

A multilocular discal cyst extending from the spinal canal to the extraforaminal region: A case report

BACKGROUND

Lumbar discal cysts are intraspinal extradural cysts communicating with the intervertebral disc. The usual location and morphology are in the caudal ventrolateral epidural space of the spinal canal, without extension to the neural foramen or crossing the midline and described as a well-defined homogeneous oval or spherical cyst on low and high signal intensities observed in lumbar lesions on T1- and T2-weighted magnetic resonance imaging, respectively. We report an unusual lumbar discal cyst in terms of the lesion location and morphology.

CASE PRESENTATION

A 33-year-old-man presented with lower back and right anterior thigh pain. Magnetic resonance imaging revealed multilocular cystic lesions in the cranial ventrolateral epidural space at L2-L3 with low and high signal intensities on T1- and T2-weighted magnetic resonance imaging, respectively. We performed a full-endoscopic transforaminal cystectomy under general anesthesia.

CONCLUSION

Lumbar discal cysts should be considered a differential diagnosis for multilocular intraspinal cystic lesion.

Postoperative discal pseudocyst and its similarities to discal cyst: A case report

BACKGROUND

Postoperative discal pseudocyst (PDP) is a rare condition that presents after surgery for lumbar disc herniation. Due to the lack of information, the diagnosis and treatment of PDP remain controversial. Herein, we report a PDP case that occurred following percutaneous endoscopic lumbar discectomy and received conservative treatment. Additionally, we review all the published literature regarding PDP and propose our hypothesis regarding PDP pathology.

CASE SUMMARY

A 23-year-old man presented with a relapse of low back pain and numbness in his left lower extremity after undergoing percutaneous endoscopic lumbar discectomy for lumbar disc herniation. Repeat magnetic resonance imaging demonstrated a cystic lesion at the surgical site with communication with the inner disc. The patient was diagnosed as having PDP. The patient received conservative treatment, which resulted in rapid improvement and spontaneous regression of the lesion, and had a favorable outcome in follow-up.

CONCLUSION

PDP and discal cyst (DC) exhibit similarities in both histological and epidemiological characteristics, which indicates the same pathological origin of PDP and DC. The iatrogenic annular injury during discectomy might accelerate the pathological progression of DC. For patients with mild to moderate symptoms, conservative treatment can lead to great improvement, even inducing spontaneous regression. However, surgical cystectomy is necessary in patients with neurological deficits and where conservative treatment is ineffective.

Clinical Application of Percutaneous Transforaminal Endoscopic Surgery in Lumbar Discal Cyst

BACKGROUND

Discal cyst is very rare and can cause intractable low back pain and radiating leg pain. Symptoms are hard to distinguish from lumbar disc herniation. The best treatment for discal cyst is controversial. Most lumbar discal cysts are treated surgically, while most studies of percutaneous transforaminal endoscopic surgery are case reports. This study investigated the clinical value of percutaneous transforaminal endoscopic surgery for lumbar discal cyst.

METHODS

A retrospective study was conducted in 9 patients with a discal cyst from June 2016 to November 2018. All patients had been treated by percutaneous transforaminal endoscopic surgery via a superior vertebral pedicle notch approach. Surgical outcomes were evaluated preoperatively and postoperatively using a visual analog scale for leg pain and the Oswestry Disability Index. At the final follow-up, patients were evaluated for clinical efficacy using modified Macnab criteria.

RESULTS

All 9 patients had remission of symptoms after removal of discal cysts. Postoperative magnetic resonance imaging showed that all patients had complete excision of discal cysts and complete decompression of the treated segment. There were no recurrent lesions during follow-up. Mean operative time was 68.67 ± 14.02 minutes. Mean hospitalization time was 4.22 ± 1.64 days. Preoperative visual analog scale and Oswestry Disability Index score improved significantly after surgery. Visual analog scale leg score improved from 7.88 ± 1.05 preoperatively to 1.78 ± 0.66 at final follow-up (P < 0.05), and ODI score improved from 53.65 ± 12.46 to 16.25 ± 8.76 (P < 0.05). According to the modified Macnab criteria, 5 patients (55.6%) were rated excellent, 3 patients (33.3%) were rated good, and 1 patient (11.1%) was rated fair at final follow-up, with an overall excellent and good rate of 88.9%. There were no serious complications during follow-up.

CONCLUSIONS

Percutaneous transforaminal endoscopic surgery could be a safe, minimally invasive surgical treatment for discal cyst, particularly suitable for patients who cannot undergo general anesthesia.

Surgical Treatment of Lumbar Spinal Discal Cyst: Is It Enough to Remove the Cyst Only without Following Discectomy?

Discal cysts are a rare cause of low back pain and radiculopathy with unknown pathophysiologic mechanism. Associated symptoms are difficult to distinguish from those caused by extruded discs and other spinal canal lesions. Most discal cysts are treated surgically, but it is unclear whether the corresponding intervertebral disc should be excised along with cyst. We conducted a retrospective clinical review of 27 patients who underwent discal cyst excision at our institution between 2000 and 2017. The mean follow-up period was 63.6 months. We recorded symptoms, radiographs, operative findings, postoperative complications, and short- and long-term outcomes. Structured outcome assessment was based on Numeric Rating Scale (NRS) for pain intensity, Oswestry disability index, and Macnab classification. All patients underwent partial hemilaminectomy and microscopic cyst resection without discectomy. All patients had preoperative back or leg pain. Other preoperative clinical features included motor weakness, neurogenic intermittent claudication, and cauda equina syndrome. After surgery, NRS scores of back and leg pain decreased. The other symptoms also improved. During long-term follow-up, patients reported no restrictions on daily life activities, and were satisfied with our intervention. There were no cases of cyst recurrence. We conducted a review of the literature on lumbar discal cysts published before January, 2018. Including our cases, 126 patients were described. We compared two surgical modalities—cystectomy with and without discectomy—to elucidate both effectiveness and long-term complications. We found that microsurgical cystectomy without corresponding discectomy is an effective surgical treatment for lumbar discal cysts, and is associated with a low recurrence rate.

Extraforaminal Discal Cyst as Cause of Radiculopathy

We report the first extraforaminal location of a lumbar discal cyst. The patient was treated by hemilaminectomy, arthrectomy, cyst resection, and unilateral arthrodesis, achieving complete release of the nerve root. Extraforaminal lumbar discal cyst may represent an unexpected cause of sciatic pain with favorable outcome after surgical resection.