Paraganglioma of the cauda equina region: A report of three cases

Cauda equina neuroendocrine tumor: a report of three cases and review of the literature with focus on differential diagnosis and postoperative management

INTRODUCTION

Cauda equina neuroendocrine tumors (CENETs), previously described as cauda equina paragangliomas (PGLs) are rare and well-vascularized benign entities which can be often misdiagnosed with other intradural tumors more common in this anatomical site, such as ependymomas and neurinomas. We describe three cases of CENETs observed at our institution with particular focus on differential diagnosis and postoperative management. Since the lack of guidelines, we performed a literature review to identify factors that can predict recurrence and influence postoperative decision making.

CASE REPORT AND LITERATURE REVIEW

We report on three patients, two of them presenting with a clinical history of lower back pain and sciatica. In all cases magnetic resonance imaging (MRI) of the lumbosacral spine with and without Gd-DTPA revealed an intradural lesion with strong contrast enhancement, first described as atypical ependymoma or schwannoma. A complete tumor resection was achieved in all cases, the histopathological diagnosis classified the tumors as CENETs. In our literature review, a total of 688 articles were screened and 162 patients were included. Patients demographic data, clinical symptoms, resection and recurrence were recorded.

DISCUSSION

Differential diagnosis between CENETs and other more common tumors affecting cauda equina region, such as ependymomas or schwannomas (neurinomas), is still very challenging. Due to the lack of specific clinical or radiological characteristics, a correct preoperative diagnosis is almost impossible. With this paper we want to point out that CENETs must be considered in the differential diagnosis, most of all in case of entities with atypical radiological features. According to the literature, tumor recurrence after gross total resection is unlikely, while a long-term follow-up is recommended in case of subtotal resection or local aggressive behavior.

A case of rare lumbar intradural tumor: paraganglioma

Lumbar paragangliomas are rare neuroendocrine neoplasms arising from specialized neural crest cells in the cauda equina/filum terminale region. They are difficult to diagnose radiologically and can be difficult to treat surgically if they secrete catecholamines. A 38-year-old woman presented with three and a half years of increasing lower back and sacrum discomfort. Her neurological examination was normal. The MRI revealed an L4 intradural lesion that was compressing the cauda equina. A total tumor resection was conducted. The paraganglioma was diagnosed by the pathology report. Paragangliomas should be considered in the differential diagnosis of intradural masses of the lumbar spine.

Resection of a lumbar intradural tumor

Background

Myxopapillary ependymomas and schwannomas represent the most common tumors of the conus medullaris and cauda equina. Here, we present the surgical resection of a 64-year-old male with a lumbar intradural tumor.

Case Description

A 64-year-old male presented with several months of the lower extremity weakness, pain, and bowel/bladder dysfunction. Magnetic resonance imaging demonstrated a large L3-5 intradural lesion, and surgical resection using intraoperative neuromonitoring with somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), free-running electromygraphy (EMGs), and direct sphincter monitoring was recommended. After an L2-S1 laminectomy was performed, intraoperative ultrasound was used to confirm the cranial and caudal extent of the tumor. The dural was opened using a midline approach, and the tumor was quickly visualized. Through careful dissection, the tumor was debulked and gross total resection was ultimately achieved through a piecemeal resection. Hemostasis was frequently required throughout the case, as the tumor was highly vascular. Postoperatively, the patient was at his neurologic baseline and was discharged to rehab on postoperative day 4. The final pathology revealed the intradural lesion was a paraganglioma.

Conclusion

Early intervention and gross total resection of spinal intradural tumors are associated with optimal patient outcomes. Additional adjuncts, such as ultrasound, are beneficial and can help achieve gross total tumor resection.

SDH-B, INSM1, and GATA3 expression in cauda equina neuroendocrine tumors: Report on 21 cases from a north Indian tertiary care centre

BACKGROUND

Primary neuroendocrine tumors (NETs) of the central nervous system (CNS) are rare, primarily seen in the cauda equina region, known as cauda equina NETs. This study was carried out to evaluate the morphological and immunohistochemical characteristics of cauda equina NETs.

MATERIAL AND METHODS

All cases of histologically proven NETs that originated within the spinal cord from 2010 to 2021 were retrieved from the surgical pathology electronic database. For each case, the clinical presentation, site, radiological features, functional status, and pre-operative diagnosis were recorded. Immunohistochemical stains for GFAP, synaptophysin, chromogranin A, cytokeratin 8/18, INSM-1, Ki67, GATA3, and SDH-B were performed for every case using automated immunostainer. GATA3 immunohistochemistry was repeated manually.

RESULTS

A retrospective probe of records revealed 21 cases of NETs having a mean age of 44 years and slight male dominance (M:F ratio 1.2:1). Cauda equina was the most prevalent site of involvement (19, 90.5%). The most typical presentation was lower backache and weakness of bilateral lower limbs. The histopathological features were similar to NETs seen at other sites. Reactivity for at least one neuroendocrine marker was seen in all cases while GFAP was negative. Cytokeratin 8/18 was expressed in the majority (88.9%) of cases. INSM1 and GATA3 expression was seen in 20 (95.2%) and 3 (14.3%) cases, respectively. All cases retained SDH-B cytoplasmic staining. Higher Ki67 index (>3%) was associated with higher risk of recurrence.

CONCLUSIONS

Cauda equina NETs rarely express GATA3 and are unlikely to be associated with SDH mutations. Recurrent cases may be negative for synaptophysin, chromogranin, and cytokeratin; thus INSM1 IHC is helpful.

Primary Paraganglioma of the Spine: A Systematic Review of Clinical Features and Surgical Management in Cauda Equina vs Non-Cauda Equina Lesions

BACKGROUND

Primary spine paragangliomas are rare tumors. Surgical resection plays a role, but aggressive lesions are challenging. We reviewed the literature on primary spine paragangliomas.

METHODS

PubMed, Scopus, Web of Science, and Cochrane were searched upon the PRISMA guidelines to include studies on primary spine paragangliomas. Clinical-radiological features, treatments, and outcomes were analyzed and compared between cauda-equina vs non-cauda-equina tumors.

RESULTS

We included 143 studies comprising 334 patients. Median age was 46 years (range, 6-85). The most frequent symptoms were lower-back (64.1%) and radicular (53.9%) pain, and sympathetic in 18 patients (5.4%). Cauda-equina paragangliomas (84.1%) had frequently lumbar (49.1%) or lumbosacral (29%) locations. Non-cauda-equina tumors were mostly in the thoracic (11.4%), thoracolumbar (5.1%), and cervical (3.6%) spine. Median tumor diameter was 2.5cm (range, 0.5-13.0). Surgical resection (98.5%) was preferred over biopsy (1.5%). Decompressive laminectomy (53%) and spine fusion (6.9%) were also performed. Adjuvant radiotherapy was delivered in 39 patients (11.7%) with aggressive tumors. Post-treatment symptomatic improvement was described in 86.2% cases. Median follow-up was 19.5 months (range, 0.1-468.0), and 23 patients (3.9%) had tumor recurrences. No significant differences were found between cauda-equina vs non-cauda-equina tumors.

CONCLUSION

Surgical resection is effective and safe in treating primary spine paragangliomas; however, adjuvant treatments may be needed for aggressive lesions.

Paraganglioma of the filum terminal: Case report and review of the literature

Paraganglioma of the filum terminal/cauda equina is a rare slow growing tumor which originates from the ectopic sympathetic neurons. Surgically, total excision may be difficult for this well demarcated tumor surrounded by couple of rootlets but is usually possible in nearly all cases. Actually, final diagnosis cannot be determined intraoperatively, but is possible only after an immunohistochemical staining. Herein, the authors present a middle age woman whose initial symptoms were lower back pain and radiculopathy. Her MRI was found to be compatible with a cauda equina tumor. During her excisional surgery a hard and relatively vascular tumor was fully removed. The Immunohistochemical results were compatible with paraganglioma of the filum terminale. In addition to case presentation, thorough review of the literature is also done.

The immunohistochemical, DNA methylation, and chromosomal copy number profile of cauda equina paraganglioma is distinct from extra-spinal paraganglioma

Paragangliomas are neuroendocrine tumors of the autonomic nervous system that are variably clinically functional and have a potential for metastasis. Up to 40% occur in the setting of a hereditary syndrome, most commonly due to germline mutations in succinate dehydrogenase (SDHx) genes. Immunohistochemically, paragangliomas are characteristically GATA3-positive and cytokeratin-negative, with loss of SDHB expression in most hereditary cases. In contrast, the rare paragangliomas arising in the cauda equina (CEP) or filum terminale region have been shown to be hormonally silent, clinically indolent, and have variable keratin expression, suggesting these tumors may represent a separate pathologic entity. We retrospectively evaluated 17 CEPs from 11 male and 6 female patients with a median age of 38 years (range 21-82), none with a family history of neuroendocrine neoplasia. Six of the 17 tumors demonstrated prominent gangliocytic or ganglioneuromatous differentiation. By immunohistochemistry, none of the CEPs showed GATA3 positivity or loss of SDHB staining; all 17 CEPs were cytokeratin positive. Genome-wide DNA methylation profiling was performed on 12 of the tumors and compared with publicly available genome-wide DNA methylation data. Clustering analysis showed that CEPs form a distinct epigenetic group, separate from paragangliomas of extraspinal sites, pheochromocytomas, and other neuroendocrine neoplasms. Copy number analysis revealed diploid genomes in the vast majority of CEPs, whereas extraspinal paragangliomas were mostly aneuploid with recurrent trisomy 1q and monosomies of 1p, 3, and 11, none of which were present in the cohort of CEP. Together, these findings indicate that CEPs likely represent a distinct entity. Future genomic studies are needed to further elucidate the molecular pathogenesis of these tumors.

[Paraganglioma of the cauda equina region: Report of 9 cases]

INTRODUCTION

The paraganglioma of the cauda equina is a rare tumor, the diagnosis is morphological and the immunohistochemistry provides a definite diagnosis. The objective of our study is to specify the clinical signs, radiological and associated pathological criteria and to compare our data with those of the literature.

PATIENTS AND METHOD

This is a retrospective study of nine cases of paragangliomas of the cauda equina diagnosed in our department from 2003 to 2018. The median age of the patients was 50 years-old with a male predominance (sex ratio: 3,5/1). All patients had preoperative magnetic resonance imaging (MRI) and surgery to remove the tumor. The diagnosis was performed after HES (Hematoxylin Eosin Saffron) and immunohistochemical sections examination.

RESULTS

Radiculalgia was the chief symptom of these tumors. MRI showed an oval lesion uniformly enhanced by Gadolinium in the eight patients whose records were available. Histologically, the tumors had a lobular and trabecular pattern with neuroendocrine-like cells and a rich vascularization. By immunohistochemistry, the cells expressed chromogranin, synaptophysin and CD56.

DISCUSSION AND CONCLUSION

Paragangliomas of the cauda equina are rare, benign tumors. Except for cases of secreting tumors, the preoperative diagnosis is difficult. MRI is useful and may reveal radiological features suggestive of these tumors. However, it is rare for the diagnosis to be made before surgery. The diagnosis is established by histological examination and immunohistochemical techniques must be used to confirm the diagnosis. The paragangliomas of the cauda equina are well encapsulated tumors whose complete excision is curative. When the excision is incomplete, treatment with radiotherapy is recommended. Long-term clinical and radiological monitoring is recommended because of the slow evolution of the tumor and the potential for recurrence.

Spinal paragangliomas: Surgical treatment and follow-up outcomes in eight cases

Paragangliomas are neuro-endocrine tumors originating from the adrenal gland. They are usually benign and nonfunctioning, rarely seen in central nervous system. More than 90% of central nervous system paragangliomas are manifested as carotid and glomus jugulare tumors. Spinal paragangliomas are quite rare.The study was conducted through retrospective analysis of the files of the patients who had undergone surgery with pre-diagnosis of spinal intradural tumor between 2011 and 2017 and diagnosed with paraganglioma.A total of 8 patients (4 females and 4 males) were included in the study. Mean age of the patients was 51.1 years (28-64). Time to admission was mean 6.5 months (3 weeks-24 months). Recurrence was not observed in 7 patients, 1 patient is being followed up due to residual tumor.Treatment may be achieved through recognizing malignant transformation in patients who were not diagnosed histopathologically. We consider that quality of life of the patients may be improved through this way.

Apoplectic presentation of a cauda equina paraganglioma

Background:

Cauda equina paragangliomas (CEPs) are rare spinal tumors that are mostly misdiagnosed preoperatively as ependymomas or schwannomas on magnetic resonance imaging (MRI). Clinically, they usually present with the gradual onset of back pain and radiculopathy rather than an acute cauda equina syndrome.

Case Description:

A 36-year-old female presented with an acute flaccid paraparesis/cauda equina syndrome. Based upon MRI studies, the predominant differential diagnoses included ependymoma or schwannoma. The intraoperative findings revealed an acute intralesional hemorrhage or apoplexy, responsible for the acute clinical deterioration. Histopathology and immunohistochemistry (IHC) revealed that the tumor was a paraganglioma.

Conclusion:

CEPs commonly present with mild symptoms and signs rather than the acute-onset of a flaccid paraparesis/cauda equina syndrome as seen in this case. Here, the authors review the radiological and histopathological characteristics of CEP and emphasize the role of IHC in differentiating “CEP” from the more common ependymomas.

Schwannomatous components in a recurrent lipomyelocele: Report of a rare case

Congenital lipomatous malformations of spinal cord constitute a diverse group of lesions and lipomyelocele is one of them. Here, we report a case of congenital lipomyelocele in a male child who presented at 7 years of age. Magnetic resonance imaging (MRI) revealed a lesion in lumbosacral region. The patient was operated and histologic examination diagnosed the case to be lipomyelocele. But after 8 years, recurrence of the lesion occurred and MRI revealed the lesion at the same location. This time histologic examination detected another new component (schwannomatous areas) in the lesion. The child was on 1-year follow-up which was uneventful.

Clinical features and surgical outcomes of primary cauda equina tumours

BACKGROUND

To identify clinical features, radiological findings and surgical outcomes of primary cauda equina tumours.

METHODS

A consecutive series of 64 operations in 60 patients with primary cauda equina tumours from April 1999 to May 2009 at one institution comprised the study. The cases were divided into tumours of neural sheath origin (TNS, n = 48) and tumours of non-neural sheath origin (TNNS, n = 22). We analysed pain intensity, neurological abnormalities, MRI findings, surgical extent and functional outcome.

RESULTS

The TNS group showed more leg pain (76 % vs. 44 %, p = 0.019) with higher intensity (6.1 ± 1.5 vs. 4.6 ± 1.9, p = 0.04). Motor weakness and bladder dysfunction were more common in the TNNS group (p = 0.028 and p = 0.00 in each). Flow voids of MRI were more frequently observed in TNNS (50 % vs. 4 %, p = 0.01). The TNS group achieved total removal in all operations compared with total removal in 77 % in the TNNS group (p = 0.001). The TNNS group showed higher recurrence rates (18 % vs. 0 %, p = 0.009). The TNS group showed higher improvement of JOA scores postoperatively (p = 0.049). Surgical complications were observed less frequently in the TNS group (19 % vs. 78 %, p = 0.000).

CONCLUSIONS

TNS differs from TNNS by causing more frequent leg pain, higher pain intensity and more frequent flow voids. TNS has better surgical outcomes than TNNS in terms of higher rates of total removal, fewer surgical complications, better functional outcomes and less recurrence.

Pancreatic paraganglioma: An extremely rare entity and crucial role of immunohistochemistry for diagnosis

Paragangliomas are rare neuroendocrine neoplasms arising in extra-adrenal chromaffin cells of autonomic nervous system and histologically akin to chemodectomas. They are rare, affecting about 1 in 2,000,000 population. It is a generic term applied to tumors of paraganglia regardless of the location. In rare instances, paragangliomas present around and involve the pancreas, thereby mimicking any one of the more common primary pancreatic lesions. Pancreatic paraganglioma is an extremely rare tumor. It grows slowly, so radical resection is recommended to achieve curability with good prognosis. These neoplasms present considerable diagnostic difficulty not only for the clinician and radiologist but also for the pathologist. Here, we report a case of a 55-year-old woman who presented with a left-sided abdominal swelling for 3 months duration, initially having clinical suspicion of an ovarian tumor. The radiological imaging revealed a lesion in the tail of pancreas with a differential diagnosis of pancreatic carcinoma and metastatic tumor. Only after exploratory laparotomy, the diagnosis was made as a rare case of pancreatic paraganglioma on the basis of histological examination and immunohistochemistry.