CT myelography and MR imaging of extramedullary cysts of the spinal canal in adult and pediatric patients

Troublemaking Lesions: Spinal Tumor Mimics

There are various mass-like lesions that can mimic true neoplasms in the spine, including inflammatory, infectious, vascular, congenital, and degenerative etiologies. While some lesions have distinctive imaging features that suggest a correct diagnosis, others have overlapping characteristics that do not allow their differentiation based solely on their imaging findings. For entities with nonspecific imaging features, knowledge of the clinical and laboratory information is critical to provide an accurate diagnosis.

Post-Spinal Anesthesia Intradural Extramedullary Arachnoid Cyst Formation: A Case Report

The formation of an intradural extramedullary arachnoid cyst is a rare complication of spinal anesthesia. We present a case of a 34-year-old female patient who developed neurological symptoms including a bilateral reduction in sensation and strength in the lower limbs following a C-section under spinal anesthesia. MRI of the thoracic spine revealed a lesion at the level of T11/T12 and the upper limit of the L1 vertebral body, which was pushing the cord to the side, and a diagnosis of the intradural extramedullary arachnoid cyst was established. The prognosis for this condition is good and surgical excision leads to resolution of the symptoms. Proper and prompt diagnosis is crucial to rule out other differentials and prevent permanent neurological damage in these patients.

Pathogenesis, management strategies, and outcome of non-communicating extradural spinal arachnoid cyst (NEAC): a systematic review

OBJECTIVE

Non-communicating extradural spinal arachnoid cysts (NEACs) are extremely rare aetiology of symptomatic spinal cord compression. The aim of this study was to address their pathogenesis, optimum management strategy and outcome through systematic review of existing published studies.

MATERIALS AND METHOD

We have found 13 eligible publications by searching through PubMed, ScienceDirect, and Google Scholar databases, published from inception to December 2020. We have analysed the data of 21 patients extracted from those 13 publications by IBM SPSS version 23.

RESULTS

According to our analysis congenital predisposition, trauma, and previous surgery history are the aetiology of NEAC. Clinical presentation of cyst depends upon the location and extent of compression or involvement of the neurovascular structures. Paraparesis with variable degree of sensory disturbance was seen among patients. Based on neuroimaging findings, NEACs are most commonly found at dorsal and dorsolumbar region. Magnetic resonance imaging (MRI) is the diagnostic modalities of choice and CT myelography can demonstrate the communication with the subarachnoid space. Recurrence rate of cyst after surgery is very low as only one out of twenty patients showed recurrence. If dural defect is not accurately addressed, the recurrence rate increased significantly.

CONCLUSIONS

Our study has highlighted aetiology, treatment strategies, and neurological outcome of NEAC. These findings may help neurosurgeons to manage this rare surgical entity for favourable outcome.

Clinical and imaging features of spinal extradural arachnoid cysts: a retrospective study of 50 cases

PURPOSE

Spinal extradural arachnoid cysts (SEDACs) are thought to arise from leakage of CSF through a spinal dural defect. This study investigates the demographics and imaging spectrum of SEDACs at our academic institution and compares them with those reported in the literature.

METHODS

Fifty cases with documented MRI diagnosis of SEDAC, Nabors criteria type I meningeal cyst (MC), were identified from retrospective review of imaging records between 1999 and 2020. Patient demographics, presenting symptoms, cyst characteristics, and management outcomes were studied. Statistical analysis was performed to determine associations between maximum cyst size and presenting symptoms along with other imaging findings.

RESULTS

In all 50 subjects, SEDACs were solitary (single) and sporadic (non-familial). The majority were incidental (62%), located posteriorly (92%) and laterally (80%) in the thoracic and thoracolumbar regions (34%, 30%). They were associated with mild mass effect upon the thecal sac (50%) and bone remodeling (92%). Among symptomatic SEDACs, back pain and radiculopathy were the most reported (68%). Larger cysts were located caudally in the spinal canal, and were associated with greater thecal mass effect, bone remodeling, and septations. Four out of six subjects who underwent surgical management had complete or partial remission. One had cyst recurrence.

CONCLUSION

In this largest series of SEDACs, most were discovered incidentally, stable over time, and located in the thoracic spine dorsal to the thecal sac. When symptomatic, back pain and radiculopathy were the most common presenting symptoms. Treatment with complete surgical excision may yield the best results for symptomatic lesions.

Imaging of intraspinal cystic lesions: A review

Several distinct conditions present as cystic or pseudocystic lesions within the spinal canal. Some of the most common spinal cystic lesions include spinal meningeal cysts, juxtafacet cysts, dermoid/epidermoid cysts, nerve sheath tumors, and syringohydromyelia. Clinical presentation is usually nonspecific and imaging characteristics are frequently overlapping, which may pose a challenging presurgical diagnosis. We provide a pictorial review of cystic intraspinal lesions and discuss the main imaging features that can aid the neuroradiologist in the differential diagnosis. First, we propose a categorization of the lesions according to their location as extradural, intradural extramedullary, and intramedullary. This is a crucial initial step in the diagnostic workup and surgical planning. Second, for each of these locations, we organize the lesions according to their etiology: congenital and developmental disorders, degenerative disorders, traumatic or postsurgical collections, infectious conditions, neoplastic lesions, and other miscellaneous disorders. Finally, we summarize the clinical highlights and MR features that provide important insights for the differential diagnosis. MR is the technique of choice in presurgical evaluation and postsurgery follow-up. It provides accurate lesion localization and characterization and, most of the times, it will allow a confident differential diagnosis. High-resolution three-dimensional T2-weighted sequences and diffusion-weighted imaging can provide important hints in specific cases. Signal correlation with T1-weighted and fat-saturated sequences allows to differentiate true cystic lesions from hemorrhage or fat tissue.

Validity of magnetic resonance imaging (MRI) in the primary spinal cord tumors in routine clinical setting

MRI is the primary diagnostic modality for spinal cord tumors. However, its validity has never been vigorously scrutinized in daily routine clinical practice, where MRI tissue diagnosis is usually not a single one but multiple ones with several differential diagnoses. Here, we aimed to assess the validity of MRI in terms of predicting the pathology and location of the tumor in routine clinical settings. We analyzed 820 patients with primary spinal cord tumors, who have a pathological diagnosis and location in the operation record which were confirmed. We modified traditional measures for validity based upon a set of diagnoses instead of a single diagnosis. Sensitivity and specificity and positive and negative predictabilities were evaluated for the tumor location and pathology. For tumor location, 456 were intradural extramedullary; 165 were intramedullary, and 156 were extradural. The overall sensitivity and specificity were over 90.0%. However, the sensitivity became lower when the tumor resided simultaneously in two spaces such as in the intradural-and-extradural or intramedullary-and-extramedullary space (54.6% and 30.0%, respectively). Most common pathology was schwannoma (n = 416), followed by meningioma (114) and ependymoma (87). Sensitivities were 93.3%, 90.4%, and 89.7%, respectively. Specificities were 70.8%, 82.9%, and 76.0%. In rare tumors such as neurofibromas, and diffuse midline gliomas, the sensitivity was much lower (less than 30%). For common locations and pathologies, the validity of MRI is generally acceptable. However, for rare locations and pathologies, MRI diagnosis still needs some improvement.

Diagnosis and treatment of noncommunicating extradural spinal thoracolumbar arachnoid cyst

Background:

Noncommunicating extradural spinal arachnoid cysts are extremely rare. They are believed to arise from congenital defects in the dura mater and become enlarged as a consequence of increased cerebro-spinal fluid (CSF) pressure within the subarachnoid space. Most retain a communicating pedicle through which the extradural cyst maintains connection with the subarachnoid space, and only rarely does this communication become sealed. The optimal treatment consists of complete surgical removal of the cyst with ligation of the communicating pedicle.

Case Description:

A 29-year-old male presented with a progressive spastic paraparesis of 6 months’ duration. The MRI showed a circumscribed intradural extramedullary cystic lesion located from D11-L2. Notably, peroperatively, the cyst appeared to be entirely extradural, without a communicating intradural pedicle. Further, no CSF leak was observed even after Valsalva maneuvers. Following surgical extirpation of the cyst, the patient sustained an uneventful recovery within 1 postoperative month.

Conclusion:

Noncommunicating extradural arachnoid cysts are extremely rare causes of spinal cord compression and should be fully excised.

Direct puncture for diagnosis of intradural spinal arachnoid cyst and fenestration using 3D rotational fluoroscopy: technical note and the "jellyfish sign"

The authors report on a 47-year-old woman with a symptomatic thoracic spinal arachnoid cyst (SAC) who underwent a novel procedure that involves direct puncture of the SAC to visualize, diagnose, and potentially treat these rare spinal lesions. The method described utilizes 3D fluoroscopy to gain access to the SAC, followed by injection of myelographic contrast into the cyst. A characteristic "jellyfish sign" was observed that represents the containment of the contrast within the superior aspect of the cyst and a clear block of cranial flow of contrast, resulting in an undulating pattern of movement of contrast within the cyst. Following balloon fenestration of the cyst, unimpeded flow of contrast was visualized cranially throughout the thoracic subarachnoid space. The patient was discharged the following day in good condition, and subsequently experienced 1 year free from symptoms. This is the first reported case of a successful direct puncture of an SAC with balloon fenestration, and the first noted real-time fluoroscopic "behavior" of CSF within an arachnoid cyst.

A Rare Case of Spinal Extradural Arachnoid Cyst with Cord Compression

Spinal extradural arachnoid cysts are rare lesions which typically involve the thoracic spine and are an asymptomatic condition of unknown origin. They may also produce symptoms by compressing the spinal cord or nerve roots. Surgery is the treatment of choice in such lesions, but asymptomatic patients can be managed conservatively. We present a case of symptomatic, probable traumatic origin, spinal arachnoid cyst at our center in Hospital Kuala Lumpur, Malaysia. Magnetic resonance imaging spine showed well-defined, nonenhancing extradural cystic lesion from T5 to T6 vertebrae level compressing spinal cord anteriorly. The patient underwent T5, T6 laminoplasty, T4 partial laminectomy and excision of the cyst. Histologically, the cyst wall comprised of collagen and meningothelial cells. This surgical intervention achieved neurological improvement in terms of motor power in our follow-up of this patient.

Dorsal cervical spinal arachnoid cyst (Type III) presenting with dorsal column dysfunction: A case report

CONTEXT

Spinal arachnoid cysts are usually asymptomatic and discovered incidentally. Expansion of the cyst, whether acute, subacute or chronic, leads to neural compression resulting in radicuopathy and/or myelopathy.

FINDINGS

This case report is of a patient who presented primarily with posterior column dysfunction,subacute in onset and rapidly progressing. Images of the cervical spine showed a dorsal arachnoid cyst, causing significant cord compression and signal changes in the cord, with no scalloping of the vertebrae.

CONCLUSION

The author explains the mechanism of rapid expansion of an asymptomatic spinal arachnoid cyst, causing neural compression leading to fast progression of neurological deficits. The dorsal location of the cyst, explain the absence of radiculopathy, which is a common presenting feature of ventrally located intradural arachnoid cyst.

Arachnoid cyst in oculomotor cistern

Oculomotor cistern is normal anatomic structure that is like an arachnoid-lined cerebrospinal fluid-filled sleeve, containing oculomotor nerve. We report a case of arachnoid cyst in oculomotor cistern, manifesting as oculomotor nerve palsy. The oblique sagittal MRI, parallel to the oculomotor nerve, showed well-defined and enlarged subarachnoid spaces along the course of oculomotor nerve. Simple fenestration was done with immediate regression of symptom. When a disease develops in oculomotor cistern, precise evaluation with proper MRI sequence should be performed to rule out tumorous condition and prevent injury of the oculomotor nerve.

An occult spinal neurenteric cyst associated with congenital hemivertebrae. A case report

We describe a case of an occult spinal neurenteric cyst associated with congenital hemivertebrae. Different intraspinal anomalies, such as neurenteric cysts (representing 0.3 to 0.5 % of all spinal tumors) have been reported in association with congenital hemivertebrae. Indeed, although CT is the best examination to study vertebral anomalies, MRI should be performed in order to exclude a more complex dysraphic condition.

A symptomatic lumbosacral perineural cyst -A case report-

Lumbosacral perineural cysts are formed by the arachnoid membrane of the nerve root at the lumbosacral level. Most of these cysts are asymptomatic and are found incidentally during computed tomography (CT) or magnetic resonance imaging (MRI) for other causes of chronic lower back pain. This type of cyst requires a differential diagnosis to distinguish it from other causes of radiating pain and neurological symptoms. In the present case, a symptomatic lumbosacral perineural cyst was found, and pain relief was achieved by non-surgical treatment. A lumbosacral perineural cyst was identified from a differential diagnosis of a lumbar disc disorder that presented as radiating pain and neurological symptoms.

Symptomatic idiopathic noncommunicating intradural arachnoid cyst of the S1 nerve root: a case report

STUDY DESIGN

A case report of a rare symptomatic, idiopathic, noncommunicating intradural arachnoid cyst (IAC) of the proximal part of the S1 nerve root (NR).

OBJECTIVE

To discuss the possible pathophysiology, clinical and magnetic resonance imaging (MRI) presentation, intraoperative findings, and follow-up of IAC of the proximal part of the S1 NR.

SUMMARY OF BACKGROUND DATA

Rare variety of the Nabors's Type 3 spinal IAC. The etiopathogenesis are uncertain. Surgical NR decompression with extirpation of the cyst is the treatment of choice.

METHODS

A 37-year-old woman clinically presented as monoradiculopathy with a 9-month history of progressive, posture-dependent radicular pain, paresthesia and hypoesthesia in the right S1 dermatome, and mild weakness of the ipsilateral plantar flexors. Magnetic resonance imaging (MRI) showed a noncommunicating IAC of the proximal part of the S1 NR on the right side. Surgical exploration through the ipsilateral L5-S1 hemilaminectomy was performed with microsurgical arachnolysis of the compressed and stretched S1 NR fascicles that surrounded the cyst, during which the cyst spontaneously collapsed. The remnant of the cyst wall was extirpated and histopathology confirmed the diagnosis.

RESULTS

After surgery an excellent clinical outcome was archived: the leg pain was no longer present and the paraesthesia, hypoesthesia, and motor weakness were resolved within 3 months. At 12 months of follow-up, the patient continues to be completely asymptomatic with no evidence of recurrence on MRI.

CONCLUSION

A rare case of symptomatic, idiopathic, noncommunicating IAC of the proximal part of the S1 NR has been presented. Early recognition and treatment resulted in complete symptom resolution, with preservation of the full working capacity and good quality of life. Isolated monoradiculopathy with progressive, posture-dependent radicular pain seem to be typical clinical findings for such a lesion. Attending physicians should always be mindful of this fact in the total clinical evaluation of such cases.

Intradural Extramedullary Arachnoid Cyst Presenting as Arteriovenous Malformation in the Thoracic Spinal Cord

We report the case of a 57-year-old man who was admitted on the basis of worsening paraplegia and incontinence. This patient had developed similar neurologic symptoms 15 previously but fully recovered after conservative medical therapy with corticosteroids. At that point, he was diagnosed with a thoracic spinal arteriovenous malformation (AVM); yet, no focal spinal lesion was identified. During this second presentation, the patient was initially worked up at an outside institution, where MR imaging revealed serpiginous flow voids along with anterior displacement or atrophy of the cord at the T5-T6 level. Edema of the mid and lower thoracic cord was also noted. While under our care, spinal arteriography and CT angiography failed to conclusively detect an underlying AVM. The patient underwent a second MR study, which showed no major interval change in the pathology. Subsequently, CT myelography of the thoracic spine demonstrated a large intradural extramedullary arachnoid cyst (or arachnoid adhesions resulting in the formation of an entrapped cystic collection). The flow voids that were seen on MR imaging were attributed to venous congestion and dilation arising from chronic compression by the cyst. Cord edema was also found to be secondary to increased interstitial pressure in the setting of this cord compression superiorly. Since surgery was not indicated for this patient at the time of diagnosis, no surgical or pathohistologic assessment was obtained to further characterize the nature of this cystic collection.

Cervical anterior intradural arachnoid cyst in a child

Intradural arachnoid cysts involving the spine are uncommon and especially rare in an anterior cervical location. In the literature, among 15 patients, 8 were in the paediatric age group and in 3 patients the cyst was localised to the full length of the cervical spinal canal. Although they occur secondary to trauma, haemorrhage, surgery or inflammation, most of them are known to be idiopathic or congenital. Although the disease shows a dramatic neurological course, early diagnosis and treatment could provide good results. We report a 2(1/2) year-old boy with progressive tetraparesis with a huge anterior intradural arachnoid cyst located from the cervico-medullary junction to the C7 level. In the paediatric age group, cervical anterior intradural arachnoid cyst is an unusual cause of quadriparesis. The rarity of this condition and the relevance of MRI in the accurate and early diagnosis is discussed here. A 2(1/2) year-old boy with a large intradural arachnoid cyst extending from the cervico-medullary junction to C7 situated anteriorly is reported here; diagnosis and treatment modalities are discussed.

Differential diagnosis of dumbbell lesions associated with spinal neural foraminal widening: imaging features

Computed tomography (CT) and magnetic resonance imaging (MRI) reliably demonstrate typical features of schwannomas or neurofibromas in the vast majority of dumbbell lesions responsible for neural foraminal widening. However, a large variety of unusual lesions which are causes of neural foraminal widening can also be encountered in the spinal neural foramen. Radiologic findings can be helpful in differential diagnosis of lesions of spinal neural foramen including neoplastic lesions such as benign/malign peripheral nerve sheath tumors (PNSTs), solitary bone plasmacytoma (SBP), chondroid chordoma, superior sulcus tumor, metastasis and non-neoplastic lesions such as infectious process (tuberculosis, hydatid cyst), aneurysmal bone cyst (ABC), synovial cyst, traumatic pseudomeningocele, arachnoid cyst, vertebral artery tortuosity. In this article, we discuss CT and MRI findings of dumbbell lesions which are causes of neural foraminal widening.

MRI of degenerative cysts of the lumbar spine

Degenerative cysts of the lumbar spine encompass a heterogeneous group of cystic lesions that are presumed to share a common aetiology. Some of these cysts may be incidental findings, whereas others may produce acute or chronic symptoms. These cysts have been categorized using various combinations of topographic and pathological characteristics and by their attachment to or communication with a specific spinal structure.

Spinal extradural arachnoid cysts: clinical, radiological, and surgical features

Extradural arachnoid cysts in the spine are rare and are seldom a cause of spinal cord compression. They are thought to arise from congenital defects in the dura mater, and they almost always communicate with the intrathecal subarachnoid space through a small defect in the dura. The mainstay of treatment in patients with neurological symptoms is surgical removal of the cyst together with ligation of the communicating pedicle and closure of the dural defect. In the present paper the authors review the literature and discuss the clinical and pathological features, mechanisms of pathogenesis, neuroimaging characteristics, and surgical management of spinal extradural arachnoid cysts. The surgical technique for removal of these lesions is illustrated in a patient with a large thoracolumbar spinal extradural arachnoid cyst causing neurogenic claudication.

Extradural spinal arachnoid cysts associated with spina bifida occulta

INTRODUCTION

Spinal extradural arachnoid cysts are an uncommon cause of neural compression in children. Even more uncommon is the association of such cysts with spina bifida occulta.

MATERIAL

Two girls, 12 and 8-years-old, presented with left leg pain, deteriorating gait, clinical signs of left L5 and S1 root compression, without bladder or bowel symptoms. The first patient had left foot drop. The second patient had muscle wasting and smaller left foot with pes cavus. Radiographs showed spina bifida occulta of S1 in both. MRI revealed an extradural cyst at the S1 level, indenting the thecal sac and the L5 and S1 roots. At operation in both patients a large arachnoid cyst arising from a small dural defect in the axilla of the left S1 root was compressing and displacing it and the dural sac. It was removed and the defect was repaired. The first patient improved with complete recovery of the foot drop. An MRI at 12 months showed no cyst recurrence. The second patient made good recovery initially, but at 10 months developed recurrent symptoms. An MRI scan showed recurrence of the cyst with root compression. On repeat exploration a different dural defect was identified in a more anterior position and was repaired.

DISCUSSION

The coexistence of extradural arachnoid cyst and corresponding bifid spinal segment has not been described previously. It raises the suspicion that the dural defect giving rise to the arachnoid cyst may be due to segmental dural dysgenesis in the context of the dysrhaphic neuroectodermal malformation.

Huge spinal extradural meningeal cyst in the thoracolumbar spine: a case report of a rare cause of low backpain

Symptomatic intraspinal extradural meningeal cysts are rare. We present the case of a 17-year-old female with low back pain, progressive numbness, and radiation pain to the flank and lower limbs. Magnetic resonance imaging and computed tomographic myelography revealed a huge intraspinal extradural meningeal cyst extending from T12 to L3 with cord and dural sac compression. The patient underwent surgery to open the cyst and close the connecting dural defect. Pathologic examination of the cyst disclosed non-specific fibrous connective tissue without an inner arachnoid single-cell lining. She achieved complete recovery after the operation. There was no recurrence of the cyst at a 2-year follow-up.

Spinal intradural juxtamedullary cysts in the adult: surgical management and outcome

OBJECTIVE

Intradural nonneoplastic cysts compressing the spinal cord are rare lesions. We retrospectively analyzed a series of patients harboring this entity with regard to clinical and radiological features, surgical management, and follow-up results.

METHODS

In a retrospective study, we reviewed the medical charts, radiological investigations, and follow-up data of 11 women and 10 men (mean age, 43.6 yr) with intradural juxtamedullary spinal cysts, which were consecutively treated microsurgically at our institutions between January 1995 and January 2003. All lesions were approached via a laminectomy, hemilaminectomy, or laminoplasty at the corresponding vertebral levels and histopathologically verified. The patients were routinely scheduled for clinical follow-up 2 and 6 months after surgery. Baseline postoperative magnetic resonance imaging (MRI) was ordered 6 months after surgery. Thereafter, follow-up was performed at 1-year intervals, with neurological examination and MRI.

RESULTS

According to presenting symptomatology, two main patient groups could be differentiated: one group with a myelopathic syndrome (10 patients) and another group with a predominant radicular pain syndrome (8 patients). Histopathological examination revealed 16 arachnoid cysts, 4 neuroepithelial cysts, and 1 cervical nerve root cyst. Most arachnoid cysts (12 cases) were located on the dorsal aspect of the thoracic spinal cord. The mean craniocaudal extension of these cysts was 3.7 vertebral levels, and complete resection was performed. In four patients, the arachnoid cyst was situated ventral to the spinal cord and involved up to 17 vertebral levels. These patients had a history of major spinal trauma, and the cyst was generously fenestrated at its greatest circumference as depicted on preoperative MRI scans. The four neuroepithelial cysts and the cervical nerve root cyst were located on the ventral or ventrolateral aspect of the spinal cord, and their maximum sagittal extension was two spinal vertebral levels. Symptoms in all but two patients demonstrated major improvement; in particular, radiating pain disappeared immediately after surgery. There was no cyst recurrence on MRI after a mean follow-up period of 3.2 years.

CONCLUSION

Intradural cysts should be considered in the differential diagnosis of lesions causing myelopathy and/or a radicular pain syndrome. Microsurgical resection or generous fenestration in cysts with large craniocaudal extensions effectively ameliorated patients' symptomatology. A description of the first documented case of a surgically treated intradural cervical nerve root cyst is provided.

MRI of spinal intradural arachnoid cyst formation following tuberculous meningitis

Secondary intradural arachnoid cyst involving the spine is uncommon. It is usually secondary to trauma, haemorrhage, surgery or inflammation. We present two cases of treated tuberculous meningitis, which presented with gradual onset of quadriplegia and paraplegia, respectively. MRI revealed intradural (cervical and thoracic) arachnoid cysts (ventral and dorsal to the spinal cord) with myelomalacic cord changes. Ventral location of such spinal arachnoid cysts, and being secondary to tuberculous arachnoiditis are distinctively uncommon features. The rarity of this condition and the relevance of MRI in the accurate diagnosis have been discussed here.

Magnetic resonance imaging—guided percutaneous fenestration of a cervical intradural cyst

✓ The authors describe the case of a high cervical, intradural extramedullary cyst located anterior to the spinal cord in a 13-year-old boy. The lesion was fenestrated percutaneously by using real-time magnetic resonance (MR) imaging guidance and a local anesthetic agent. The patient's symptom, severe exercise-induced headache, immediately resolved after treatment. Nine months later, complete disappearance of the cyst was confirmed on MR imaging and computerized tomography myelography. Magnetic resonance imageing—guided fenestration can be considered a minimally invasive option for intradural cystic lesions.