Unusual sequestered disc fragments simulating spinal tumors and other space-occupying lesions

Posterior endoscopic cervical discectomy with partial pediculotomy for management of highly down-migrated cervical disc herniation: A case report

Background

Highly migrated cervical disc herniations are rare, and the optimal surgical approach remains uncertain. When located in the median or paramedian position, anterior cervical discectomy and fusion or anterior cervical corpectomy and fusion are preferentially selected, whereas posterior approaches are often considered for cases with radiculopathy.

Case Description

A 40-year-old woman presented with right C6 radicular symptoms without any specific triggering event. She initially experienced symptom relief through medication and an ultrasound-guided nerve block 4 years previously. The symptoms recurred 2 months before presentation and did not improve with conservative treatment. Magnetic resonance imaging revealed a paramedian herniation on the right side, migrating downward from the C5/6-disc level to the inferior border of the pedicle. Posterior endoscopic cervical discectomy (PECD) with partial pediculotomy was performed under general anesthesia with transcranial motor-evoked potential monitoring. The operative time was 56 min. The patient experienced immediate symptom relief, mobilized 3 h postoperatively, and was discharged the following day.

Conclusion

PECD with partial pediculotomy is a minimally invasive and effective option for treating highly down-migrated cervical disc herniation, offering reduced tissue disruption, faster recovery, and excellent clinical outcomes.

Sequestered Lumbar Disc Mimicking Psoas Abscess: A Case Report

We present a rare case of a sequestered lumbar disc herniation mimicking a psoas abscess. A 68-year-old male with a history of tongue cancer surgery had a ring-enhancing lesion in the left psoas muscle at the L2/3 level on contrast-enhanced computed tomography (CT), raising concerns about psoas abscesses related to vertebral spondylodiscitis. Magnetic resonance imaging (MRI) revealed a well-defined mass with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and surrounding muscle edema. CT-guided biopsy revealed degenerative intervertebral disc tissue without malignancy or acute inflammation, confirming a sequestered disc herniation as the cause. Sequestered disc herniation is a rare condition in which the disc material migrates away from its origin, presenting similarly to infections or tumors. Imaging features such as ring enhancement in contrast studies can complicate the diagnosis. This case highlights the importance of considering sequestered disc herniation in the differential diagnosis of psoas muscle masses. Further research is needed to better understand the pathophysiology and management of sequestered disc herniation in the psoas muscle.

Posterior epidural migration of thoracic and lumbar disc material: a comprehensive 63-year systematic review with anatomical perspectives

This study aims to thoroughly investigate the clinical presentation, duration of symptoms, radiological aspects of posterior epidural migration of disc fragments (PEMDF), and assess various treatment options and their impacts on patient functionality. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We conducted a comprehensive search in PubMed, Web of Science, and Scopus from inception to March 2024. Patient demographic and clinical outcomes data were extracted from articles that met the inclusion criteria. The extracted data included patients' age, sex, duration of symptoms (months), clinical presentation, diagnostic imaging, PEMDF spinal level, surgical technique used, and functional outcome and clinical improvement with follow-up (months). The primary outcomes of interest were total recovery (complete resolution of neurological deficits), partial recovery (clinical improvement with residual neurologic deficits), stable status (no change from the patient's baseline), and worst outcome (new symptoms or neurological deficits appearing post-surgical treatment). This review examined 105 studies on the pathology of posterior epidural migration of disc fragments, including 29 case series and the remainder as case reports, involving a total of 175 patients. The median age of the cohort was 54 years (range, 19-95), with 75.61% male and 24.39% female. Symptoms lasted a median of 0.5 months (range, 0.1-120 months), with cauda equina syndrome (45.7%) as the most common presenting symptom, followed by radiculopathy (34.3%) and lower back pain (21.1%). A history of heavy lifting was reported in 10.7% of patients. In terms of treatment, 5 patients (2.9%) were managed conservatively, while 162 (92.6%) underwent laminectomy. Additional interventions included minimally invasive interlaminar surgery (3 patients, 1.7%), transforaminal lumbar interbody fusion (2 patients, 1.1%), interlaminar lumbar interbody fusion (1 patient, 0.6%), and endoscopic spine surgery (2 patients, 1.1%). Functional outcomes showed symptomatic improvement in 173 patients (98.9%), with one patient remaining stable and one experiencing worsening symptoms. Partial recovery occurred in 42 patients (24%), while 131 patients (74.9%) achieved total recovery. Our study highlights the rarity and diagnostic complexity of posterior epidural migration of disc fragments. Prompt and precise diagnosis is crucial to prevent further neurological decline. Surgical intervention to remove sequestered disc fragments has demonstrated excellent functional and clinical outcomes.

Direct epidural metastasis of breast cancer mimicking a large lumbar disc sequestrum: A case report and review of literature

We report a case of cauda equina syndrome (CES) caused by an epidural metastasis of breast cancer, which oddly mimicked a large disc sequestrum leading to misdiagnosis. To our knowledge, it is the first report of a metastatic epidural breast cancer lesion mimicking a disc sequestrum.

Posterior epidural intervertebral disc migration and sequestration: A systematic review

Posterior epidural intervertebral disc migration and sequestration (PEIMS) is a rare and debilitating complication of degenerative disc disease. Radiological differential diagnosis is often challenging, complicating the accurate planning of appropriate treatment strategies. We systematically reviewed the literature on PEIMS, focusing on clinical-radiological features and available treatments. PubMed, Scopus, Web of Science, and Cochrane were searched to include studies reporting clinical data of patients with PEIMS. Clinical characteristics, treatment strategies, and functional outcomes were analyzed. We included 82 studies comprising 157 patients. Median age was 54 years (range, 19-91). PEIMSs occurred spontaneously (49.7%) or acutely in patients with underlying progressive degenerative disc disease (50.3%). The most common symptoms were lower-back pain (77.1%) and radiculopathy (66.2%), mainly involving the L5 nerve root (43.8%). PEIMSs were mostly detected at MRI (93%) and/or CT (7%), frequently located in the lumbar spine (81.5%). Median maximum PEIMS diameter was 2.4 cm (range, 1.2-5.0). Surgical debulking was completed in 150 patients (95.5%), sometimes coupled with decompressive laminectomy (65%) or hemilaminectomy (19.1%). Median follow-up time was 3 months (range, 0.5-36.0). Post-treatment symptomatic improvement was reported in 153 patients (97.5%), with total recovery in 118 (75.2%). All 7 patients (4.5%) who received conservative non-surgical management had total clinical recovery at ≤ 3 months follow-ups. PEIMS is a challenging entity that may severely quality-of-life in patients with degenerative disc disease. Surgical removal represents the gold standard to improve patient's functional status. Spine fusion and conservative strategies proved to be effective in some cases.

Sequestered disc herniation mimicking psoas abscess: A rare case report

Intervertebral disc herniation is common condition, with majority occurring in lumbar and cervical spine. Most lumbar disk herniations occur within the spinal canal, with approximately 7%-10% identified within the foramen or extraforaminal location. Extraforaminal disc herniation in extreme lateral, retroperitoneal or anterior terms are used when disc material is seen towards anterolateral or anterior to the spine. Disc herniation in these locations is easily mistaken for an abscess or a neoplasm especially when it is not connected to the parent disc (sequestered disc). We describe a case of 60-year male who initially was misdiagnosed as psoas abscess and subjected to invasive investigation which later turned out to be histologically confirmed disc sequestration in the retroperitoneum. Thus, knowledge of this condition is essential in avoiding unnecessary workup and treatment.

Sequestrated Lumbar Disc Herniation Mimicking Spinal Neoplasm

Sequestered disc fragments do not have indistinctive features and often share the clinical and radiological presentation as spinal neoplasms making their diagnosis and treatment a clinical challenge.

We report a rare case of sequestered lumbar disc fragment at the level of L2-L3 in a 70-year-old male who presented to the ER complaining of six years' history of low back pain with acute onset lower extremities weakness for six days, associated with right foot drop. He was admitted for tumor workup as the MRI showed diffuse bone high signal intensity throughout the spine with a soft tissue epidural mass at L2/3, causing severe compression on the cauda equina nerve roots. The patient underwent L2-L3 decompression and fixation, mass excision, multiple open biopsies. Soft tissue biopsy of the mass revealed fibrocartilaginous tissue consistent with the intervertebral disc, while the bone biopsy was diagnostic of acute leukemia. The patient was observed postoperatively with unremarkable complications. He did well with physiotherapy, and there was a remarkable improvement of his right lower extremity power reaching 4/5.

Our case presented a rare phenomenon in which sequestered disc fragments manifested clinically and radiologically as a spinal neoplasm. Vigilant history taking and physical examination are paramount; a physician should be watchful for any red flags that may warrant further investigation such as in our case.

Lumbar disc sequestration through the dura into the intrathecal space presenting as acute cauda equina

A 64-year-old man was referred to A&E by his general practitioner with worsening back and acute bilateral leg pain and weakness with urinary retention. His MRI scan demonstrated spinal canal stenosis at the level of L1-L2 and a diagnosis of cauda equina syndrome (CES) was made. CES is a rare neurological condition caused by compression of the central spinal nerves at the termination of the cord. CES is a surgical emergency requiring urgent assessment and treatment. The patient underwent urgent surgical decompression; however, he required a second surgery for further decompression as repeat MRI showed persistent stenosis with further extension. Intraoperative Doppler ultrasonography revealed an intradural lesion, which was surgically excised and found to be a sequestrated lumbar disc in the intrathecal space. The patient showed significant neurological improvement post revision decompression.

Spinal extradural arteriovenous fistula after lumbar epidural injection: CT angiographic diagnosis using 3D-volume rendering

Spinal extradural arteriovenous fistulas (SEDAVFs) are a rare form of spinal arteriovenous fistulas, the etiology of which has not been completely elucidated. To our knowledge, this is the first reported case of SEDAVF that may have been caused by a spinal procedure. This report describes a 50-year-old female patient who presented with an SEDAVF at the L3/4 level that developed 3 years after a transforaminal epidural block due to disc extrusion, after which she underwent no other operation or trauma. From routine spine magnetic resonance imaging, disc sequestration was considered more likely than vascular malformation. However, on lumbar CT angiography (CTA) and three-dimensional volume rendering images (3D-VRI), the lesion showed good association with arteries of the aortic branches, allowing us to confirm the exact diagnosis of the lesion as SEDAVF. A limitation of 3D-VRI reconstruction is the difficulty in separate visualization of the vertebral body and blood vessels. On follow-up CTA, 3D dual-energy computed tomography (DECT) depicted smaller vascular structures and showed their anatomical relationships to the bone. While spinal angiography has been traditionally known as the gold standard for SEDAVF diagnosis, CTA with 3D-VRI, especially obtained by DECT, allows clinicians to make an accurate diagnosis and treatment plan that are difficult to judge by routine MRI.

Intradural lumbar disc herniations at the L1-L2 level: A case study and literature review

Background

Intradural disc herniations (IDHs) are rare occurrences (0.26-0.30%), and most frequently involve the lumbar spine at the L4-L5 level. Here, we present a patient with an L1-L2 IDH and reviewed the current literature.

Case Description

A 65-year-old female presented with the acute onset of bilateral paraparesis accompanied by urinary dysfunction. The lumbar MRI showed a mass at the L1-L2 level with caudal migration, accompanied by a positive "hawk-beak" sign. At surgery, consisting of a L1-L2 laminectomy, a large IDH was encountered responsible for marked cauda equina/root compression. Postoperatively, the patient immediately fully recovered. The literature we identified cited just seven similar studies of L1-L2 IDH.

Conclusion

In a 65-year-old female, an IDH was anticipated at the L1-L2 level due to the combined MR findings of a large L1-L2 mass with caudal migration and the positive "hawk-beak" sign.

Vertebral fracture with muscle hematoma mimicking abscess

Vertebral fracture with muscle hematoma is occasionally seen in practice. However, air-containing hematoma mimicking abscess has not been reported. We present an 87-year-old man with back pain after a fall. Computed tomography scan demonstrated vertebral fracture of L1 and low-density lesions with air bubble in the left crus of the diaphragm and left psoas muscle that were verified to be muscle hematoma. Muscle hematoma due to vertebral fracture can present radiological findings similar to an abscess. A characteristic “vertebral body cleft continuity sign” might be useful for differentiating between hematoma and abscess.

Degenerative Disc Disease Mimicking Spondylodiscitis with Bilateral Psoas Abscesses

BACKGROUND

Sequestered disc fragments may present as a lesion with peripheral enhancement on magnetic resonance imaging. When located in the psoas muscle compartment, this finding could mimic an abscess.

CASE DESCRIPTION

We describe a case of a 52-year-old man who returned from Togo after 2 years of living in precarious conditions. He was afebrile and complaining of lumbar back pain. The magnetic resonance imaging showed L3 and L4 vertebral body enhancement with bilateral psoas lesions in continuity with the disc space, suggesting spondylodiscitis with a differential diagnosis of inflammatory herniated disc. A computed tomography-guided biopsy of the right psoas lesion was performed to rule out spondylodiscitis. Histology was compatible with extruded disc material.

CONCLUSION

Herniated disc fragments should be considered as a differential diagnosis of psoas abscesses. Coronal plane images may show the continuity of bilateral herniated disc fragments, mimicking psoas abscesses.

Misdiagnosis of posterior sequestered lumbar disc herniation: report of three cases and review of the literature

Introduction

Posterior migration of sequestered disc is an extremely rare event that mimics more common spinal lesions as spinal tumors, making difficult its preoperative diagnosis and appropriate management. We retrospectively reviewed all lumbar disc herniations treated by surgery at our institution from 2006 to 2016 to identify cases with posterior sequestered disc fragments and possible misdiagnosis for other spinal lesions. Complementarily, a literature review of misdiagnosed cases of posterior migrated discs was undertaken.

Case report

Three posterior sequestered lumbar disc cases (one intradural), were found among the 1153 reviewed surgeries. Two of them, presenting with progressive neurological deficit, were respectively misdiagnosed as pseudotumoral lesion and meningioma/neurogenic tumor on MRI. After intraoperative diagnosis and emergent resection, histology confirmed intervertebral disc tissue. The remaining case had an accurate preoperative diagnosis and after an initial conservative management finally underwent surgery because of refractory pain. Full recovery was achieved months after surgical treatment in all cases.

Discussion

Non-tumoral lesions are the most frequent misdiagnosis of posterior sequestered lumbar disc described in the literature. Early surgical treatment is the standard management due to high incidence of cauda equine syndrome (CES); however, spontaneous regression of posterior sequestered lumbar disc herniations has been recently reported. In conclusion low incidence and similar clinical and radiological features with other more common posterior spinal lesions like hematomas, synovial cyst or abscess turns posterior sequestered disc herniations a diagnosis challenge. Despite high incidence of CES, an initial conservative management should be evaluated in selected patients without neurological deficit and well-controlled pain.

Anterior discectomy could still be an alternative to corpectomy in highly migrated cervical disc herniation

OBJECTIVE

For cases of cervical disc herniation, highly migrated cervical disc (HMCD) is clinically rare and usually treated with anterior cervical corpectomy and fusion (ACCF). This study aims to analyze the feasibility of anterior cervical discectomy and fusion (ACDF) for the patients with HMCD.

METHOD

Clinical data of 32 patients with HMCD treated with ACDF or ACCF were retrospectively reviewed. Migration distances of the disc prolapses were measured. The mJOA score was used to evaluate surgical effect.

RESULTS

ACDF was successful in 27 patients while ACCF was used for the remaining 5 because of epidural disc prolapse adhesion or unreachable migrated fragments. Complete spinal cord decompression without residual disc fragments was observed in postoperative MRI of all cases. The mean migration distance of the disc prolapses in ACDF group was 7.3 mm, comparing to 11.4 mm in ACCF group. No disc prolapse in ACDF group exceeded the axial length of the vertebral bodies while three of five in ACCF group did. Preoperative mean mJOA scores in ACDF group and ACCF group were 8.20 ± 2.75 and 6.10 ± 2.15, respectively. Postoperative mean mJOA scores in those two groups were significantly improved to 14.70 ± 1.55 (p < .001) and 12.80 ± 1.72 (p < .001), with an improvement rate of 72.80 ± 4.76% and 62.90 ± 9.46%, respectively.

CONCLUSION

ACDF is feasible for patients with HMCD except for cases of epidural disc prolapse adhesion or huge disc prolapse which migrates over the axial length of the vertebral body. Clinical symptoms can be significantly improved with few serious complications in those patients including ones underwent alternative ACCF due to a failed ACDF.

Dorsal Lumbar Disc Migrations with Lateral and Ventral Epidural Extension on Axial MRI: A Case Series and Review of the Literature

Dorsal epidural migration of lumbar disc extrusion is rare and commonly misdiagnosed. Our purpose was to retrospectively analyze soft-tissue abnormalities on axial MR imaging in both the ventral and lateral epidural space in such dorsal epidural migrations. The presence of each component required complete concordance by 3 independent neuroradiologist readers. In a case series (n = 6) of surgically proved dorsal lumbar disc migrations, in which the radiologist's favored prospective diagnosis had not been correct, each case demonstrated epidural soft-tissue abnormality that had components both laterally and ventrally, abutting the parent disc. Similarly, in previously published cases for which axial MR imaging was available, the lateral component was demonstrated in 23/24 cases (96%). Ventral abutment of the parent disc was evident, in addition, in 17/18 cases (94%) with available disc-level axial images. Both ventral and lateral epidural soft-tissue abnormalities are typically present in dorsal lumbar disc herniations and may help radiologists suggest this rare diagnosis in appropriate cases.

Far caudally migrated extraforaminal lumbosacral disc herniation treated by a microsurgical lateral extraforaminal transmuscular approach: case report

A 33-year-old man presented with moderate low-back pain and L-5 radiculopathy that progressed to severe paresis of L-5. On initial imaging, a corresponding spinal lesion was overlooked. Further CT and contrast-enhanced MRI demonstrated a presacral mass along the L-5 root far extraforaminally. A herniated disc was suspected, but with standard imaging a schwannoma could not be ruled out. The presacral L-5 root was explored via a microsurgical lateral extraforaminal transmuscular approach. To the best of the authors' knowledge, there have been no reports of sequestered extraforaminal lumbosacral disc herniations that herniated into the presacral region.

Atypical Presentation of a Sequestered Posterolateral Disc Fragment

Sequestered disc fragments typically occur ventrally but can also migrate dorsally or intradurally. At times, atypical disc herniations can be misinterpreted on imaging as other lesions, such as neoplasms, hematomas, or abscesses. We present an uncommon case of a patient presenting with cauda equina syndrome secondary to an enhancing sequestered disc fragment mimicking a tumor.

Postdural disc herniation at L5/S1 level mimicking an extradural spinal tumor

INTRODUCTION

Postdural disc herniation has been documented rarely and the pathogenesis is still unknown. The average age of postdural disc herniations is between 50 and 60 years, and the sites most frequently affected by postdural lumbar disc herniations are L3-L4 and L4-L5, only less than 10 % in L5-S1. Although magnetic resonance imaging (MRI) is a useful tool in the diagnosis of this disease, the postdural disc herniation is usually misdiagnosed as extradural spine tumor preoperatively. The definitive diagnosis is made during operation or according to the postoperative pathology.

METHODS

In this article, we described here a 48-year-old male patient who presented with intermittent pain in the low back and frequent urination for 4 years as well as hypesthesia and pain of the left lower extremity for 1 month.

RESULTS

A standard total laminectomy was performed and the histopathological diagnosis was consistent with a degenerated intervertebral disc. The patient presented significant relief of the pain and of the neurological symptoms, but no improvement of frequent urination, in the postoperative period.

CONCLUSIONS

The diagnosis of postdural disc herniations is very difficult and mainly based on intraoperative and histopathological results. Early surgical intervention is important to relieve symptoms and prevent severe neurological deficits.

Posterior epidural migration of lumbar intervertebral fragment: case report

Disc fragments are well known to migrate to superior, inferior, or lateral sites in the anterior epidural space, posterior epidural migrated lumbar disc fragments is an extremely rare disorder. Posterior epidural migrated lumbar disc fragments are often confused with other posterior epidural space-occupying lesions (cysts, abscesses, tumors, and hematomas). We reported the case of a 52- year-old man presented with progressive not systematizes bilateral radiculopathy complicated one week before admission a difficulty dorsiflexion prevents the start, and the stared to use crutches. Clinical examination revealed steppage gait and a strength score of 3/5 on dorsiflexion of feet. MR imaging of lumbar spine showed right posterolateral epidural mass that compressed the dural sac at the L3-4 level. Patient underwent surgery using posterior approach, an L3 laminectomy was performed, the extruded disk fragment was gently removed and L3-L4 interspace was explored. Histopathology confirmed the (PEMLIF). Postoperative course was uneventful.

Spontaneous regression of posterior epidural migrated lumbar disc fragments: case series

BACKGROUND CONTEXT

Posterior epidural migrated lumbar disc fragments is an extremely rare disorder. Surgical treatment was performed in all reported cases. To the best of our knowledge, there are no reported cases of the use of conservative treatment for posterior epidural migrated lumbar disc fragments.

PURPOSE

To report the possibility of a spontaneous regression of posterior epidural migrated lumbar disc fragments.

STUDY DESIGN

Case series.

METHODS

Four patients with posterior epidural migrated lumbar disc fragments were treated at Karatsu Red Cross Hospital between April 2008 and August 2010. Spontaneous regression of the posterior epidural migrated lumbar disc fragments with relief of symptoms was observed on magnetic resonance imaging (MRI) in three cases. Another patient underwent surgical treatment. The present and previously reported cases of posterior epidural migrated lumbar disc fragments were analyzed with respect to patient age, imaging features on MRI, the level of the lesion, clinical symptoms, treatment, and outcomes.

RESULTS

Conservative treatment was successful, and spontaneous lesion regression was seen on MRI with symptom relief in three cases.

CONCLUSIONS

Although posterior epidural migrated lumbar disc fragment cases are generally treated surgically, the condition can regress spontaneously over time, as do sequestrated disc fragments. Spontaneous regression of lumbar disc herniations is a widely accepted observation at present. Posterior epidural migrated lumbar disc fragments fall under the sequestrated type of disc herniation. In fact, the course of treatment for posterior epidural migrated lumbar disc fragments should be determined based on the symptoms and examination findings, as in cases of ordinary herniation. However, providing early surgical treatment is important if the patient has acute cauda equina syndrome or the neurologic symptoms worsen over time.

Voluminous free disk fragment mimicking an extradural tumor

A 56-year-old man presented with a rare case of a voluminous herniated disc fragment mimicking an intraspinal extradural tumor on magnetic resonance (MR) imaging. He had experienced low back pain and sciatica in his right leg for 12 months, which exacerbated suddenly 4 days before admission accompanied by right quadriceps muscle weakness. MR imaging with gadolinium demonstrated a tumor-like longitudinal lesion, extending from the L1-2 to the L3-4 intervertebral disc spaces and occupying most of the right half of the vertebral canal. L2 and L3 laminectomy, as well as L2-3 right foraminotomy, were performed. We were prepared for an oncological operation, but instead, a huge disc fragment was removed en bloc from the right epidural space. The patient's postoperative course was uneventful and he demonstrated full neurological recovery within 2 months. Sequestrated lumbar disc fragments must be considered in the differential diagnosis of longitudinal extradural mass lesions in the spinal canal independently of their size. MR imaging with contrast medium can differentiate herniated disc from tumors and other epidural lesions. Nevertheless, nontypical sequestrated disc herniations are extremely rare and can be misinterpreted.

Posterior epidural migration of sequestered lumbar disc fragment causing cauda equina syndrome

Posterior epidural migration (PEM) of a sequestered free lumbar disc fragment is rare. The rarity is due to presence of several anatomical restraints which restrict a free fragment to move to the posterior compartment. This unusual presentation of disc herniation appeared in the literature either as a single case report or in small series from two to six cases. Herein two new demonstrative cases will be presented with a brief review of the literature.

Sequestered disc fragment mimicking a psoas abscess

BACKGROUND CONTEXT

If a herniated lumbar disc fragment extrudes and migrates away from the spinal column, the radiographic appearances can be confusing.

STUDY DESIGN

In this article, we report a rare case of a sequestrated disc fragment in the psoas muscle, discrete from the adjacent disc space, which presented with features similar to a psoas abscess on imaging studies.

CONCLUSIONS

It is vital that in such cases the correct diagnosis is made to avoid unnecessary treatments and inappropriate management.

Posterior epidural migration of sequestrated cervical disc fragment: case series

Study Design

A retrospective study was undertaken to delineate the characteristics of non-traumatic sequestrated epidurally migrated cervical disc prolapse.

Purpose

To present first case series of eight such cases diagnosed preoperatively and to discuss their magnetic resonance imaging (MRI) characteristics and their management.

Overview of Literature

Non-traumatic spontaneous migration of the sequestrated disc fragment epidurally behind cervical vertebral body is rare. Only ten cases have been reported in literature.

Methods

Detailed clinico-radiological profiles of these 8 cases are presented. In six cases their clinical picture was suggestive of cervical myelopathy. MRI scan showed single level epidural migrated disc behind body of C4, C6, and C7 in six patients and two cases with multiple levels (C5-C6). In six cases, anterior corpectomy with excision of the disc was performed and the seventh patient underwent dorsal laminectomy. The eighth patient chose not to undergo surgery.

Results

T1 images of the MRI scan showed an isointense signal in all the 8 cases. T2 images revealed a varying intensity. In six cases who underwent anterior corpectomy, there was a rent in the posterior longitudinal ligament. Among those in two cases multiple disc fragments were seen. In the rest four cases, a single large fragment was observed. These patients improved after anterior corpectomy and disc excision. There was no improvement in the patient who had undergone dorsal laminectomy. The eighth patient who refused surgery progressively deteriorated.

Conclusions

We opine that MRI scan especially T1 images are useful in these cases. We prefer to treat these cases through anterior corpectomy with excision of the sequestrated disc which proved to result in excellent outcome.

Posterior epidural migration of a lumbar disc fragment: a series of 6 cases

OBJECTIVE

The migration of a lumbar intervertebral disc fragment to the posterior epidural space is a rare complication of lumbar disc herniation (LDH), mostly diagnosed intraoperatively. The authors describe a series of 6 patients with a posterior epidural migration of a lumbar intervertebral disc fragment (PEMLIF) and provide a systematic review of the literature.

METHODS

The authors undertook a retrospective case series of patients with PEMLIF who underwent surgery for LDH between February 2007 and June 2010. In 6 (1.04%) of 572 patients a diagnosis of PEMLIF was established. In addition, a systematic review of the literature produced 41 additional cases reported since 1973. The authors analyzed epidemiological, clinical, and imaging features, as well as surgical treatment and outcome of this infrequent form of LDH.

RESULTS

This study represents the largest case series to analyze the distinguishing features of PEMLIF. Including the authors' cases, 37 male (78.72%) and 10 female (21.28%) patients (mean age 54.08 years) appear in the literature. Although the predominant clinical disturbance was related to cauda equina compression in 22 patients (46.80%), 19 patients (40.42%) presented with typical symptoms of sciatica or anterior thigh pain. In 27 patients (57.44%), PEMLIFs were localized at high lumbar levels. Magnetic resonance imaging was used in 36 cases. The PEMLIF appeared iso- to hypointense on T1-weighted imaging and had a variable intensity on T2-weighted imaging. After administration of Gd, 85.71% of lesions exhibited a peripheral ring. The preoperative diagnosis was never related to PEMLIF in 68% of cases. The PEMLIF was totally resected in all patients. An additional discectomy was performed in 31 patients (65.95%). Information was incomplete in 1 case. Of the remaining 46 patients, all improved postoperatively: total recovery was achieved in 33 cases (71.74%), subtotal recovery in 2 cases (4.35%), and improvement in 11 cases (23.91%). The postoperative outcome appeared not to depend on the duration or the degree of preoperative neurological deficits or the size of disc fragment.

CONCLUSIONS

The migration of a lumbar intervertebral disc fragment to the posterior epidural space is a rare event, occurring in an advanced working-age population. Clinical presentation is indistinguishable from the typical LDH, but overall cauda equina symptoms are far more common. High lumbar levels are more affected. Magnetic resonance imaging characteristics are difficult to differentiate from those of other entities. Ring enhancement after Gd administration is common. Outcomes in patients with cauda equina symptoms appear better than those in patients with standard ventral compression.