Two cases in which 3D MRI was used to differentiate between a disc mass that mimics a tumor and neurinoma

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.

Differential Diagnosis of Mimicking Tumor Discs Using Coronal Magnetic Resonance Imaging of Three-Dimensional Fast-Field Echo with Water-Selective Excitation: A Single Center Retrospective Study

OBJECTIVE

As disc fragment completely loses contact with the parent disc and can migrate in all directions of the epidural space, making it appear similar to schwannoma, it is fairly difficult to make a definitive diagnosis for mimicking tumor discs. The aim of this research is to differentially diagnose mimicking tumor discs and schwannomas using coronal magnetic resonance imaging (MRI) of three-dimensional fast-field echo with water-selective excitation (CMRI).

METHODS

Among 76 patients (38 men and 38 women; mean age, 52.88 ± 15.80 [range, 18-78 years]) who were retrospectively examined in this study, 38 were primarily diagnosed with schwannomas and pathologically diagnosed with mimicking tumor discs after surgery, and 38 were primarily diagnosed with neurogenic tumors and pathologically diagnosed with schwannomas after surgery. Open surgery was performed in all the patients between March 2016 and April 2020. The preliminary diagnosis of all patients was considered an intraspinal tumor based on conventional two-dimensional MRI sequences. After open surgery, the final diagnosis was confirmed to mimic a tumor disc or schwannoma based on postoperative pathology reports. The sensitivity, specificity, and reliability of CMRI and conventional MRI for identifying mimicking tumor discs and schwannomas were compared. Chi-square and McNemar tests were used for statistical analyses.

RESULTS

Symptoms were considerably relieved in all the patients after surgery. Seven patients had grade 1 extensor digitorum longus, triceps surae, or quadriceps femoris muscle strength prior to surgery. No nerve root injury was observed in any of the patients. CMRI showed significantly higher sensitivity (94.74%) and specificity (94.74%) than conventional MRI (71.05% and 92.11%, respectively; p = 0.012 < 0.05, and p = 1 > 0.05, respectively) for differential identification between mimicking tumor discs and schwannomas. Moreover, CMRI showed a higher reliability (kappa value = 0.787) than conventional MRI (kappa value = 0.374).

CONCLUSIONS

CMRI is a better non-invasive technology for the identification of intraspinal lesions, especially for differentiating between mimicking tumor discs and schwannomas.

Case Report: The Coronal Magnetic Resonance Imaging of Three-Dimensional Fast-Field Echo With Water-Selective Excitation Can Identify the Wrapping of Spinal Nerve Fibers Into Subdural Tumors Prior to Operation

Purpose

In the present study, the authors intend to identify the spatial relationship between subdural tumors and spinal nerve fibers of cauda equina prior to operation using the coronal MRI of three-dimensional fast-field echo with water-selective excitation (CMRI).

Methods

In total, 30 case series with surgically and pathologically verified subdural tumors were enrolled in the present study. The spatial relationship between subdural tumors and spinal nerve fibers of the cauda equina was assessed via conventional MRI and CMRI by three experts prior to operation. The spatial relationship between subdural tumors and spinal nerve fibers of the cauda equina was classified using CMRI. The accuracy of imaging observation was determined via intraoperative observation.

Results

Though conventional MRI and gadolinium (Gd)-enhanced MRI (Gd MRI) cannot identify the spatial relationship between subdural tumors and spinal nerve fibers of cauda equina in all cases, CMRI can identify it prior to operation and divide the spatial relationship of spinal nerve fibers of cauda equina with subdural tumors into three types. CMRI shows higher sensitivity (97.44%) and specificity (90.47%) in identifying the spatial relationship of spinal nerve fibers of cauda equina with subdural tumors. Additionally, CMRI also showed a substantial agreement with a kappa value of 0.78.

Conclusion

Herein, the authors first describe a potential novel application that CMRI can successfully identify the spatial relationship between subdural tumors and spinal nerve fibers of cauda equina prior to operation, which play an essential role in making a prudent surgical plan and preventing postoperative nerve damage.

Summary

Intraoperative observation confirms spinal nerve fibers of cauda equina are often wrapped into subdural tumors of the thoracolumbar and lumbar region, which can result in a high rate of sensory and motor dysfunction after the operation due to the unconscious about the wrapping of nerves into subdural tumors prior to operation. To date, there is not an effective strategy to identify the wrapping before operation.

Lumbar disc sequestration mimicking a tumor: Report of four cases and a literature review

BACKGROUND

Disc herniation refers to the displacement of disc material beyond its anatomical space. Disc sequestration is defined as migration of the herniated disc fragment into the epidural space, completely separating it from the parent disc. The fragment can move in upward, inferior, and lateral directions, which often causes low back pain and discomfort, abnormal sensation, and movement of lower limbs. The free disc fragments detached from the parent disc often mimic spinal tumors. Tumor like lumbar disc herniation can cause clinical symptoms similar to spinal tumors, such as lumbar soreness, pain, numbness and weakness of lower limbs, radiation pain of lower limbs, etc. It is usually necessary to diagnose the disease according to the doctor's clinical experience, and make preliminary diagnosis and differential diagnosis with the help of magnetic resonance imaging (MRI) and contrast-enhanced MRI. However, pathological examination is the gold standard that distinguishes tumoral from non-tumoral status. We report four cases of disc herniation mimicking a tumor, and all the pathological results were intervertebral disc tissue.

CASE SUMMARY

The first case was a 71-year-old man with low back pain accompanied by left lower extremity radiating pain for 1 year, with exacerbation over the last 2 wk. After admission, MRI revealed a circular T2-hypointense lesion in the spinal canal of the L4 vertebral segment, with enhancement on contrast-enhanced MRI suggesting neurilemmoma. The second case was a 74-year-old man with pain in both knees associated with movement limitation for 3 years, with exacerbation over the last 3 mo. MRI revealed an oval T2-hyperintense lesion in the spinal canal at the L4–5 level, with obvious peripheral enhancement on contrast-enhanced MRI. Thus, neurilemmoma was suspected. The third case was a 53-year-old man who presented with numbness and weakness of the lumbar spine and right lower extremity for 2 wk. MRI revealed a round T2-hyperintense lesion in the spinal canal at the L4–5 level, with obvious rim enhancement on contrast-enhanced MRI. Thus, a spinal tumor was suspected. The fourth case was a 75-year-old man with right lower extremity pain for 2 wk, with exacerbation over the last week. MRI revealed a round T1-isointense lesion in the spinal canal of the L3 vertebral segment and a T2-hyperintense signal from the lesion. There was no obvious enhancement on contrast-enhanced MRI, so a spinal tumor was suspected. All four patients underwent surgery and recovered to ASIA grade E on postoperative days 5, 8, 8, and 6, respectively. All patients had an uneventful postoperative course and fully recovered within 3 mo.

CONCLUSION

Disc herniation mimicking a tumor is a relatively rare clinical entity and can be easily misdiagnosed as a spinal tumor. Examinations and tests should be improved preoperatively. Patients should undergo comprehensive preoperative evaluations, and the lesions should be removed surgically and confirmed by pathological diagnosis.

Imaging and histopathologic features of reversible nerve root and peripheral nerve edema secondary to disc herniation in a cat

Nerve root enlargement with increased contrast uptake has been reported in dogs and humans secondary to nerve root compression. In cats, nerve root enlargement and contrast uptake only have been reported in association with inflammatory and neoplastic diseases, but not as a sequela to nerve root compression. An 8‐year‐old oriental short hair cat was presented with acute neurologic deficits consistent with left‐sided sciatic nerve deficit and possible L6‐S1 myelopathy. Magnetic resonance imaging (MRI) was performed and identified compression of the cauda equina and L7 nerve root associated with intervertebral disc herniation (IVDH) at L6‐L7 as well as widespread sciatic nerve enlargement with moderate rim enhancement. A hemilaminectomy was performed to evacuate herniated disc material. The nerve root was biopsied and submitted for histological evaluation. Interstitial nerve edema was diagnosed. Follow‐up MRI 3 months postoperatively showed complete remission of the changes. Nerve root thickening together with contrast enhancement may represent nerve edema in cats secondary to IVDH.

Clinicopathologic Features of Thoracolumbar Interdural Disc Herniations: A Retrospective Case Series with a Systematic Literature Review

BACKGROUND

Transdural disc herniations represent about 0.3% of all herniated discs. Preoperative imaging rarely demonstrates this condition. Therefore, diagnosis of transdural disc herniation is usually made intraoperatively. We describe the clinicopathologic features of extremely rare cases of thoracic and lumbar interdural disc herniations mimicking spinal intradural en plaque tumors.

METHODS

This is a retrospective case series with a systematic literature review. Clinical presentation, imaging, differential diagnosis, intraoperative microsurgical findings, and possible pathogenesis were reviewed according to published guidelines. All patients underwent a posterior approach for microsurgical excision of disc herniation, but no epidural lesion was found. At intradural exploration, a tumor-like en plaque lesion was discovered. The surface of the lesion was incised, and multiple friable, cartilaginous white-yellow fragments were removed to achieve complete intralesional excision.

RESULTS

The postoperative course was characterized by progressive neurologic improvement in all cases. In peculiar anatomic (adhesions between the anulus fibrosus, posterior longitudinal ligament, and ventral surface of dura mater) and pathologic (calcified giant disc herniation, spinal canal stenosis, previous lumbar spine surgery) conditions, penetration of disc fragment in the thickness of spinal dura mater can occur.

CONCLUSIONS

Interdural disc herniations constitute a rare pathologic condition characterized by the migration of the herniated disc in neither the epidural nor the subdural spinal space, but rather in the thickness of the spinal dura mater. Further advances are necessary in neuroradiologic investigations to achieve a correct preoperative diagnosis, which is essential, as spine surgeons must be aware of these rare pathologies.

Coronal magnetic resonance imaging of three-dimensional fast-field echo with water-selective excitation improves the sensitivity and reliability of identification of extraforaminal lumbar disc herniation

Objective

The complete view of the nerve root, including the extraforaminal zone, can be displayed by coronal magnetic resonance imaging (MRI) of three-dimensional (3D) fast-field echo with water-selective excitation (CMRI). However, its sensitivity, specificity, and reliability for the diagnosis of extraforaminal lumbar disc herniation are unclear. We compared the sensitivity, specificity, and reliability of conventional MRI, CMRI, and 3D MRI for the identification of extraforaminal lumbar disc herniation.

Methods

This study involved 140 patients (68 with extraforaminal lumbar disc herniation and 72 with paramedian disc herniation). Their mean age was 44.57 ± 14.59 years. Conventional MRI, CMRI, and 3D MRI of all patients were evaluated by five experts. The reliability, sensitivity, and specificity of the three imaging techniques for identification of extraforaminal lumbar disc herniation were compared using kappa statistics and the chi-squared test.

Results

CMRI showed higher agreement (0.843) than conventional MRI (0.671) and 3D MRI (0.771) for the identification of extraforaminal lumbar disc herniation. CMRI demonstrated higher sensitivity (95.6% vs. 91.2%) than conventional MRI (85.3% vs. 70.6%) and 3D MRI (92.6% vs. 86.7%) regardless of whether performed by junior or senior surgeons.

Conclusions

CMRI is helpful for identification of extraforaminal disc herniation by junior and senior orthopedic surgeons.