A pure fluid-filled intradural cyst associated with intradural disc herniation and possible pathogenesis: a case report

Background contextLumbar intradural disc herniation (IDH) is rare, and intradural cyst associated with IDH is quite rare. Only seven cases of an intradural cyst associated with lumbar disc herniation have been reported, and all were gas-filled cysts. We report the first case, to our knowledge, of a fluid-filled intradural cyst associated with IDH.PurposeTo report an extremely rare case of a fluid-filled intradural cyst associated with lumbar IDH and suggests the possible pathogenesis.Study designCase report.MethodsAn 82-year-old woman presented with right leg pain and motor weakness. Computed tomography and magnetic resonance imaging (MRI) scans showed calcified lumbar disc herniation and an intradural cystic mass at the L1–L2 level. An MRI, which was performed 2 years before admission, showed an IDH without a cyst at the same level.ResultsSurgical resection of the intradural cyst was performed. Intraoperative finding showed a fluid-filled intradural cyst with 1-cm diameter of displacing nerve rootlets. The cyst was connected with extradural cystic components through a ventral dural hole, but the tract was blocked by fibrous septum. Histopathologic examination showed a pseudocyst that consisted of degenerative cartilaginous and fibrous tissues, including degenerative disc materials. We concluded that the cyst was an intradural cyst transformed from the intradural disc fragment.ConclusionsThe current case is the first report to our knowlege of a fluid-filled intradural cyst associated with IDH. The possible mechanism may be focal degeneration and spontaneous absorption of the intradural disc with fluid production. Unlike the gas-filled intradural cysts, the cause of the pure fluid-filled cyst may be disconnection from the intervertebral vacuum because of a calcified disc and septation of the cyst.     

Gas-filled intradural cyst with migration into the nerve root of the cauda equina

Only 4 cases of gas-filled intradural cysts of the spine have been reported previously. All cysts were due to intradural herniation of a gas-containing disc. The authors report 2 additional patients with gas-filled intradural cysts that migrated into the nerve root of the cauda equina. After surgical treatment their severe leg pain completely resolved.     

Cervical intradural disc herniation

STUDY DESIGN: A case report of anterior en bloc resected cervical intradural disc herniation and a review of the literature. OBJECTIVE: To discuss the pathogenesis of cervical intradural disc herniation. SUMMARY OF BACKGROUND DATA: Including this study case, only 17 cases of cervical intradural disc herniation have been reported. There have been few detailed reports concerning the pathogenesis of cervical intradural disc herniation. METHODS: A cervical intradural disc herniation at C6-C7, with localized hypertrophy and segmentally ossified posterior longitudinal ligament, is reported in a 45-year-old man who had Brown-Sequard syndrome diagnosed on neurologic examination. Neuroradiologic, operative, and histologic findings, particularly the pathology of the anterior en bloc resected posterior vertebral portion of C6 and C7, were evaluated for discussion of the pathogenesis. RESULTS: Adhesion of dura mater and hypertrophic posterior longitudinal ligament was observed around a perforated portion of the herniated disc, and histologic study showed irregularity in fiber alignment accompanied by scattered inflammatory cell infiltration and hypertrophy in the posterior longitudinal ligament. The cervical intradural disc herniation was removed successfully and followed by C5-Th1 anterior interbody fusion with fibular strut graft. Neurologic recovery was complete except for minor residual sensory disturbance in the leg 7 years after the surgery. CONCLUSIONS: Cervical intradural disc herniation is an extremely rare condition. The pathogenesis remains obscure. Only 16 cases have been reported in the literature, and there has been little discussion concerning the local pathology of the herniated portion. The pathogenesis of the disease in the patient reported here was considered to be the adhesion and fragility of dura mater and posterior longitudinal ligament. This was caused by hypertrophy, with chronic inflammation and ossification of the posterior longitudinal ligament sustaining chronic mechanical irritation to the dura mater, leading to perforation of the herniated disc by an accidental force.     

Extensive intradural arachnoid cyst of the lumbar spinal canal: case report

BACKGROUND: Spinal intradural arachnoid cysts are rare outpouchings of arachnoid lining occurring mainly in the thoracic and cervical regions. MRI is considered the diagnostic procedure of choice; however, some arachnoid cysts have been reported to elude diagnosis by MRI due to the similar signal intensity of the cyst and the subarachnoid space. CASE DESCRIPTION: We present a case of a 41-year-old woman with an intradural arachnoid cyst of the lumbar spinal canal. Diagnostic studies demonstrated a herniated L4-5 disk, which led to two operations. Despite intractable pain postoperatively, the MRI failed to reveal further focal compression of the nerve root. A myelogram suggested compression of the thecal sac by a dorsal mass lesion. The patient underwent a midline durotomy that revealed two large arachnoid cysts with the nerve roots beneath them pushed ventrally and to the right. Removal of the arachnoid layer resulted in complete fenestration of the cyst and allowed the nerve roots to freely float in the spinal fluid. CONCLUSION: In retrospect, the abnormality could be appreciated on multiple prior scans performed at another institution, demonstrating that in the patient with low back pain, degenerative disc disease is not the only diagnosis to consider.     

Acute formation of lumbar discal cyst: what is the mechanism?

Lumbar discal cysts are extremely rare pathologies, with only few reports describing these lesions in the literature. Moreover, their definite pathogenesis is still unknown, with proposed theories based on radialogic and histologic findings. In this report, the authors present an acute formation of a discal cyst, which is reported for the first time. Also, we center our case on the discussion of the possible pathogenesis. Also, this is the first case of discal cyst reported in Turkey. A 67-year-old woman, whose complaints, and clinical and radiological findings demonstrated lumbar disc herniation with acute Modic 1 degererative changes of the adjacent end plates of L3-4 level. After medical and physical therapies, follow-up lumbar MRI has been taken to demonstrate a discal cyst formation on the adjacent intervertebral disc, showed cranially migrated cyst superior posterior on herniated disc, in 2 weeks period. The patient was treated by microsurgical resection of the cyst, and her complaints resolved completely.     

Microsurgery for intradural epidermoid cyst at cauda equina level in a 9-year-old child: A case report

Introduction and importanceEpidermoid cysts are rare benign tumors. Here, we present a case of spontaneous intradural epidermoid cyst at cauda equina level in a 9-year-old patient, which we believed the first case to be reported in Vietnam.Case presentationA 9-year-old boy presented with 4 months of spontaneous left lower extremity muscle weakness and paresthesia. The MRI images suggested the diagnosis of intradural epidermoid cyst at cauda equina level. The patient underwent L5–S1 laminectomy and durotomy for tumor resection. The histology confirmed the diagnosis of epidermoid cyst. Post-operative images demonstrated total cyst removal.Clinical discussionThe epidermiology, presentation and diagnosis and strategy of treatments as well as their outcomes were discussed.ConclusionDiagnosis of spinal epidermoid cyst is often delayed for its obscure presentation. Microsurgical dissection along with intra-operative mobile C-Arms enable total tumor resection while preserving spinal stability and neurological function. Follow-up with post-operative magnetic resonance imaging and tumor marker are helpful.     

Intraoperative ultrasound imaging in lumbar disc herniation surgery

Summary The diagnosis of lumbar disc herniation has improved with metrizamide rhizography and CT. Also, visualization of the operative site has been enhanced with use of the operating microscope. However, evaluation of the completeness of herniated disc removal can be difficult, especially in the case of medially located lesions. Also, intradural extension of the herniation can be impossible to rule out in some cases without intradural exploration. Intraoperative ultrasound imaging is safe, rapid and readily available in most hospitals. Its application to real-time imaging control of 10 selected cases of herniated lumbar disc showed that the herniated material could be visulalized in relation to the interspace and dural sac in all cases. The effect of removal of the herniation on nerve root compression could also be evaluated. Especially in cases involving extension of the herniation to the medial region under the dura, or into the intradural space, the removal of herniated material could be adequately confirmed without the need for further manipulation with surgical instruments. With appropriate transducer design and frequency, the method can be applied to microsurgical technique to rule out sequestration outside of the surgical exposure.     

Symptomatic secondary spinal arachnoid cysts: a systematic review

BACKGROUND CONTEXTSecondary spinal arachnoid cysts have rarely been reported but present significant challenges for management. These cysts could be anteriorly located with long rostral–caudal extensions and many are related to arachnoiditis, leading to difficult-to-treat disorders. Thus far, due to the scarcity of reports, the features of the disease and the optimal therapeutic strategies remain unclear.PURPOSETo investigate clinical features and the optimal treatment modalities of secondary spinal arachnoid cysts compared with primary spinal arachnoid cysts.STUDY DESIGNSystematic review.PATIENT SAMPLESystematic review identified 103 secondary cases from 80 studies and reports.OUTCOME MEASURESCondition of symptom relief and duration of treatment response were analyzed.METHODSAn electronic literature search of the PubMed database was conducted for studies on secondary spinal arachnoid cysts between 1990 and 2022. Non-English publications, nonhuman studies, reports of a primary cyst, studies not including case details, and studies of nonsymptomatic cases were excluded.RESULTSThis systematic review included 103 secondary cases. The most commonly reported etiologies were iatrogenic factors, trauma, and subarachnoid hemorrhage, accounting for 88 intradural extramedullary, 11 extradural, one intradural/extradural, one interdural, and one intramedullary spinal arachnoid cyst after a median duration of 30, 12, and 9 months, respectively. Extradural cysts were more prone to occur at dorsal locations and affect thoracic segments (mean cyst length: 3.4 segments). Intradural cysts showed a relatively higher ventral/dorsal ratio (1:1.09, 1.75:1, and 3.50:1 for cysts occurring from iatrogenic factors, trauma, and subarachnoid hemorrhage, respectively) and thoracic distribution, with a mean cyst length of 4.3 segments (5.1 for ventral and 3.5 for dorsal cysts). For intradural cysts, recurrence risk was lower after surgical resection than after fenestration/marsupialization (12-month recurrence risk: 21.43% vs 50.72%, log-rank test: p=.0248, Gehan–Breslow–Wilcoxon test: p=.0126). In cases treated with shunting, one recurrence (1/8 cases) was noted after external shunting and two recurrences (2/5 cases) after internal shunting at a median follow up of 12 months.CONCLUSIONSSecondary spinal arachnoid cysts, particularly intradural cysts, are rarer and more challenging to treat than primary spinal cysts. Although fenestration/marsupialization is the commonly adopted treatment, the recurrence rate is high. For unresectable cysts, shunting procedures, particularly shunting into a body cavity (eg, pleural or peritoneal cavity) away from the subarachnoid space, could be a therapeutic alternative besides fenestration/marupialization, yet its efficacy requires confirmation by more data.     

Lumbar intradural extramedullary bronchiogenic cyst

The pathological findings of an intradural and extramedullary cyst at the L1 level of the spinal canal are described in a 28-year-old male who presented with chronic lumbago and progressive weakness and numbness in both lower limbs. Histopathological examination revealed the diagnosis of bronchiogenic cyst. Bronchiogenic cysts in the spinal canal are uncommon, and cysts at the L1 level are extremely rare. Their pathogenesis is still poorly understood. They are thought to be a malformation arising from a split notochordal syndrome. We conclude that intradural extramedullary bronchiogenic cysts may appear also at lumbar levels. Surgical resection can be achieved with good outcome.     

Spontaneous resorption in recurrent intradural lumbar disc herniation. Case report

The authors report a case of spontaneous resorption of intradural disc material in a patient with recurrent intradural lumbar disc herniation and review magnetic resonance (MR) imaging and histopathological findings. Intradural lumbar disc herniation is rare, and most patients with this condition require surgical intervention due to severe leg pain and vesicorectal disturbance. In the present case, however, the recurrent intradural herniated mass had completely disappeared by 9 months after onset. Histological examination of intradural herniated disc tissue demonstrated infiltrated macrophages and angiogenesis within the herniated tissue, and Gd-enhanced MR images showed rim enhancement not only at the initial presentation, but also at recurrence. The authors conclude that when rim enhancement is present on Gd-enhanced MR images, there is a possibility of spontaneous resorption even though the herniated mass may be located within the intradural space. Moreover, when radiculopathy is controllable and cauda equina syndrome is absent, conservative therapy can be selected.     

A gas filled intradural cyst associated with disc degeneration

A case of a lumbar intradural, extramedullary gas filled cyst is described. This was associated with degenerative disc disease and presented with radicular signs and symptoms. The radiological differential diagnosis of such a mass includes infection and tumours. The association of intradural gas with degenerative disc disease is previously reported. This case further illustrates the association of degenerative disc disease with an intradural gas filled cyst and provides an interesting radiological differential diagnosis for an extramedullary intradural mass.     

Pathogenesis of the discal cysts communicating with an adjacent herniated disc. Histological and ultrastructual studies of two cases

Discal cyst of the lumbar spine is a very rare cause of back pain and sciatica. We report two cases of discal cysts communicating with an adjacent herniated disc. From CT and MRI findings, they were diagnosed as having a discal cyst in the epidural space, which compressed the nerve root. After an adequate surgical field was obtained with a microscope and a Casper retractor, the discal cyst could be excised and satisfactory decompression of the adjacent nerve root was obtained. From histological and electron microscopic study, the presence of residual herniated tissues was confirmed in the cyst wall. Macrophages played an important role in the absorption of herniated tissue and the formation of the discal cyst. Hemorrhage in the cyst wall will make the serous hemorrhagic fluid-filled cystic structure in the absorbed spaces of the prolapsed disc. In this study, we confirmed that the discal cyst could have developed from the absorption process of a disc herniation.     

Lumbar intervertebral disc cyst as a cause of radiculopathy.

BACKGROUND CONTEXT: Lumbar radiculopathy is commonly caused by degenerative conditions such as a herniated disc or lumbar spinal stenosis. Less common etiologies include intraspinal extradural masses such as synovial cysts and gas-containing ganglion cysts. Intraspinal extradural cysts that communicate with the intervertebral disc are a rare entity and thus, an uncommon cause of lumbar radiculopathy. There are only ten cases of an intervertebral disc cyst reported in the literature. PURPOSE: To document the first reported case of an intervertebral disc cyst in North America. Two series of Japanese patients with intervertebral disc cyst confirmed radiographically and intraoperatively have recently been reported. STUDY DESIGN: A case report of an intervertebral disc cyst at L4-5 causing an L5 radiculopathy. OUTCOME MEASURES: Japanese Orthopaedic Association score for low back pain. METHODS: The patient and the authors involved in the patient's management were interviewed. All medical records, radiographic imaging studies, intraoperative findings, and pertinent literature were also reviewed. RESULTS: Preoperative magnetic resonance imaging (MRI) scan demonstrated a well-localized cyst compressing the ventral aspect of the thecal sac at L4-L5. Discography and subsequent computed tomographic (CT) scanning demonstrated the cyst communicating with an intervertebral disc herniation via an annular rupture. Decompressive discectomy and surgical excision of the disc cyst from the spinal canal resulted in complete recovery and resolution of the preoperative radiculopathy. Clinical improvement was documented using the JOA scoring system. Patient's preoperative score was 4/15, and postoperative score was 15/15. CONCLUSION: Although exceedingly rare, an intervertebral disc cyst should remain in the differential diagnosis of any extradural intraspinal mass ventral to the thecal sac. Diagnosis of an intervertebral disc cyst requires recognition of this uncommon entity and a high index of suspicion. Discography and post-discography computerized tomography (CT) scan confirm the diagnosis. Operative treatment includes decompression, and excision of the cyst and is reserved only for cases in which the cyst results in clinical symptoms unresponsive to nonoperative management.     

Nerve root compression by a gas-containing cyst associated with stenotic lateral recess. Case report and review of the literature.

The authors describe a case in which a gas-containing cyst was associated with a stenotic lateral recess at the same level in the absence of any disc material. A young man presented a one-month history of sciatica caused by compression of the left L5 nerve root. The neuroradiological investigations performed (CT, MRI) showed the presence of a gas-containing cyst associated with a stenotic lateral recess. The clinical, etiopathological characteristics and treatment of this condition are discussed and the pertinent literature is reviewed. Decompression of the nerve root was obtained by surgery. The herniated gas collected within a capsule (gas-containing cyst) can act as a mass and produce symptoms, much like a herniated nucleus pulposus. The antalgic stance adopted by the patient with marked flexion of the spine helps to distribute the pressure exerted by the cyst over a wider area (Pascal's law I). The appropriate procedure to relieve the radicular compression caused by gas-containing cyst seemed to be the surgical treatment.     

Thoracic Myelopathy Secondary to Intradural Extramedullary Bronchogenic Cyst

Abstract

Background/Objective: To report a case of thoracic myelopathy secondary to intradural extramedullary bronchogenic cyst.

Study Design: Case report.

Methods/Findings: A 20-year-old man presented to the emergency department with increasing back pain and lower-extremity weakness. Magnetic resonance imaging demonstrated a cystic lesion at the T4 level with mass effect on the spinal cord.

Results: The lesion was resected, and histopathologic evaluation showed a cyst lined by respiratory-type epithelium consistent with a bronchogenic cyst.

Conclusions: Intradural extramedullary bronchogenic cysts of the thoracic spine have been reported previously but are extremely rare. The treatment of choice is surgical resection.     

Intradural disc mimicking: a spinal tumor lesion

STUDY DESIGN: A case report of intradural disc hernia mimicking an intradural extramedullary spinal tumor lesion in radiological evaluation. OBJECTIVE: To describe a lumbar intradural disc herniation with atypical radiological appearance and point out the role of contrast magnetic resonance imaging (MRI) of the lumbar spine. SETTING: Turkey. CASE REPORT: A 58-year-old man with suspected lumbar intradural mass and neurological involvement received L5 total laminectomy. L5 total laminectomy was performed, and on inspection dura was swollen and immobile. A longitudinal incision was made in the dura and an intradural-free disc fragment was removed. The patient's postoperative period was uneventful and he had full recovery in 3 months. CONCLUSIONS: Lumbar intradural disc rupture must be considered in the differential diagnosis of mass lesions causing nerve root or cauda equina syndromes. Contrast-enhanced MRI scans are useful to differentiate a herniated disc from a disc space infection or tumor. This case demonstrates the role and the importance of contrast MRI in the diagnosis of intradural disc herniation.     

Radicular compression due to lumbar intraspinal gas pseudocyst: case report

A case of sciatic pain syndrome is reported. Computed tomography showed evidence of gas in the spinal canal, and at operation a gas-filled pseudocyst was found in the spinal canal, without herniated disc. The cause of this unique case is discussed in relation to the spinal vacuum phenomenon.     

Primary Spinal Intradural Extramedullary Hydatid Cyst in a Child

Abstract

Background/Objective: Spinal hydatid cyst is a serious form of hydatid disease affecting less than 1% of the total cases of hydatid disease. We present a case of pathologically confirmed primary intradural spinal cyst hydatid in an otherwise healthy patient who showed no other evidence of systemic hydatid cyst disease.

Case Report: An 8-year-old boy presented with back pain, left leg pain, and difficulty in walking. The patient had no other signs of systemic hydatid cyst disease. An intradural extramedullary cystic lesion was identified with magnetic resonance imaging and was shown to be a hydatid cyst by histopathologic examination after the surgical removal.

Conclusion: Although extremely rare, primary intradural extramedullary hydatid cyst pathology might be the cause of leg pain and gait disturbance in children living in endemic areas.     

Intraspinal cyst communicating with the intervertebral disc in the lumbar spine: discal cyst.

STUDY DESIGN: A retrospective case study of patients with intraspinal cyst having a distinct connection with the corresponding intervertebral disc. OBJECTIVES: To propose a new clinical entity, "discal cyst," by clarifying the clinical, radiographic, and histologic aspects of the disease. SUMMARY OF BACKGROUND DATA: Several types of intraspinal cysts with different pathogenesis, causing symptoms indistinguishable from those of lumbar disc herniation, have been reported, such as perineural cysts, synovial cysts, and ganglion cysts. However, to the authors' knowledge, no detailed analysis has been made of cysts that have a distinct connection with the corresponding intervertebral disc. METHODS: Clinical pictures, radiographic findings, and surgical and histologic findings in eight surgically treated patients with intraspinal cyst having a distinct connection with the intervertebral disc were reviewed. Possible pathogenesis and a proposal for nomenclature were also discussed. RESULTS: This disease can be characterized by (1) clinical symptoms indistinguishable from those of typical disc herniation, manifesting as a unilateral single nerve root lesion; (2) incidence at slightly younger age and at upper intervertebral levels than with typical disc herniation; (3) T1 low signal and T2 high signal intensity, round to oval mass lesion on magnetic resonance imaging, compatible with a liquid-containing cyst; (4) minimal degeneration of the involved disc, either on discography/computed tomographic discography or magnetic resonance imaging; (5) a connection between the cyst and the corresponding intervertebral discs on discograms with severe radiating pain in the affected leg at the time of injection; (6) immediate relief of symptoms after simple removal of the cyst; (7) cyst wall consisting of dense fibrous connective tissue containing bloody to clear serous discharge; and (8) absence of disc materials and a specific lining cell layer on histologic examination. Although the exact cause is unknown, underlying minor disc injury may serve as a basis for cyst formation. CONCLUSION: Eight cases of intraspinal cysts communicating with the intervertebral disc presenting symptoms identical to those of disc herniation are presented. Because all cysts were connected to the corresponding disc and the development of the cyst was assumed to be related to underlying disc injury, it is proposed to name this clinical entity discal cyst.     

Restoration of compressive loading properties of lumbar discs with a nucleus implant—a finite element analysis study

Background ContextDiscectomy is a common procedure for treating sciatica. However, both the operation and preceding herniated disc alter the biomechanical properties of the spinal segment. The disc mechanics are also altered in patients with chronic contained herniation. The biomechanical properties of the disc can potentially be restored with an elastomeric nucleus replacement implanted via minimally invasive surgery.PurposeThe purpose of this study was to determine whether the compressive characteristics of the intervertebral disc after a nucleotomy can be restored with an elastomeric nucleus replacement.Study DesignA finite element model of the L4–L5 intervertebral disc was created to investigate the effect of the implantation of an elastomeric nucleus replacement on the biomechanical properties of the disc under axial loading.MethodA L4–L5 physiologic intervertebral disc model was constructed and then modified to contain a range by volume of nucleotomies and nucleus replacements. The material properties of the nucleus replacement were based on experimental data for an elastomeric implant. The compressive stiffness, radial annular bulge, and stress distribution of the nucleotomy and nucleus replacement models were investigated under displacement-controlled loading.ResultsRemoval of nucleus pulposus from the physiologic disc reduced the force necessary to compress the disc 2 mm by 50%, altered the von Mises stress distribution, and reduced the outward radial annular bulge. Replacing the natural nucleus pulposus of the physiologic disc with an artificial nucleus reduced the force required to compress the disc 2 mm by 10%, indicating a restoration of disc compressive stiffness. The von Mises stress distribution and annular bulge observed in the disc with an artificial nucleus were similar to that observed in the physiologic disc.ConclusionThis study demonstrates that despite having different material properties, a nucleus replacement implant can restore the axial compressive mechanical properties of a disc after a discectomy. The implant carries compressive load and transfers the load into annular hoop stress.