Cauda equina tumor with ependymal and paraganglionic differentiation

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.

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 cauda equina: a tertiary centre experience and scoping review of the current literature

Cauda equina paragangliomas are rare benign extra-adrenal neuroendocrine tumours arising from the neural crest cells associated with autonomic ganglia. These tumours are often mistaken preoperatively for ependymomas or schwannomas. Patients present with axial or radicular pain with or without neurological deficits. Recurrence, secretory features and length of follow-up are controversial. We conducted a retrospective cohort study of paraganglioma through searching a prospectively maintained histopathology database. Patient demographics, presentation, surgery, complications, recurrence, follow-up and outcome between 2004 and 2016 were studied. The primary aim was to collate and describe the current evidence base for recurrence and secretory features of the tumour. The secondary objective was to report outcome and follow-up strategy. A scoping review was performed in accordance with the PRISMA-ScR Checklist. Ten patients were diagnosed (M:F 7:3) with a mean age of 53.6 ± 5.1 (range 34–71 years). MRI scans revealed intradural lumbar enhancing lesions. All patients had complete microsurgical excisions without adjuvant therapy with no recurrence with a mean follow-up of 5.1 ± 1.4 years. Tumours were attached to the filum terminale. Electron microscopic images demonstrated abundant neurosecretory granules with no evidence of catecholamine production. A total of 620 articles were screened and 65 papers (including ours) combining 121 patients (mean age 48.8 and M:F 71:50) were included. The mean follow-up was 3.48 ± 0.46 (range 0.15–23 years). Back pain was the most common symptom (94%). Cure following surgery was achieved in 93% of the patients whilst 7% had recurrence. Total resection likely results in cure without the need for adjuvant therapy or prolonged follow-up. However, in certain situations, the length of follow-up should be determined by the treating surgeon.

Primary paraganglioma of the spine: A clinicopathological study of eight cases

Context:

Spinal paragangliomas are rare neuroendocrine tumors of the extra-adrenal paraganglionic system.

Aims:

This study describes the clinicopathological features of eight cases of spinal paraganglioma and highlights the significance of important morphological features and immunohistochemistry in the diagnosis of paraganglioma at this unusual site.

Material and Methods:

All the cases of primary spinal paragangliomas diagnosed during the last six years (2008-2013) in the Department of Pathology at our hospital were reviewed.

Results:

There were six males and two females. The mean age at diagnosis was 50.4 years. All patients presented with low back pain. All tumors were located in the cauda equina or conus medullaris region. Magnetic Resonance Imaging and intraoperative appearance were that of a vascular, well-circumscribed intradural, extramedullary tumor suggestive of either schwannoma or ependymoma. All the patients underwent gross total resection of the tumor. Histopathology in five of the cases showed ‘ependymoma-like histology’ while only three cases had a predominant classic ‘zellballen’ pattern. Two cases had prominent ‘gangliocytic differentiation’. In the five cases with ‘ependymoma-like histology’, the diagnosis was confirmed on Immunohistochemistry (IHC).

Conclusions:

Even though relatively rare, paraganglioma should be considered in the differential diagnosis of spinal tumors and due to their clinical, radiological and histopathological similarity to schwannoma and ependymoma, the diagnosis should be based on close examination of the clinical, radiological and pathological findings.

Paragangliomas: update on differential diagnostic considerations, composite tumors, and recent genetic developments

Recent developments in molecular genetics have expanded the spectrum of disorders associated with pheochromocytomas (PCCs) and extra-adrenal paragangliomas (PGLs) and have increased the roles of pathologists in helping to guide patient care. At least 30% of these tumors are now known to be hereditary, and germline mutations of at least 10 genes are known to cause the tumors to develop. Genotype-phenotype correlations have been identified, including differences in tumor distribution, catecholamine production, and risk of metastasis, and types of tumors not previously associated with PCC/PGL are now considered in the spectrum of hereditary disease. Important new findings are that mutations of succinate dehydrogenase genes SDHA, SDHB, SDHC, SDHD, and SDHAF2 (collectively "SDHx") are responsible for a large percentage of hereditary PCC/PGL and that SDHB mutations are strongly correlated with extra-adrenal tumor location, metastasis, and poor prognosis. Further, gastrointestinal stromal tumors and renal tumors are now associated with SDHx mutations. A PCC or PGL caused by any of the hereditary susceptibility genes can present as a solitary, apparently sporadic, tumor, and substantial numbers of patients presenting with apparently sporadic tumors harbor occult germline mutations of susceptibility genes. Current roles of pathologists are differential diagnosis of primary tumors and metastases, identification of clues to occult hereditary disease, and triaging of patients for optimal genetic testing by immunohistochemical staining of tumor tissue for the loss of SDHB and SDHA protein. Diagnostic pitfalls are posed by morphological variants of PCC/PGL, unusual anatomic sites of occurrence, and coexisting neuroendocrine tumors of other types in some hereditary syndromes. These pitfalls can be avoided by judicious use of appropriate immunohistochemical stains. Aside from loss of staining for SDHB, criteria for predicting risk of metastasis are still controversial, and "malignancy" is diagnosed only after metastases have occurred. All PCCs/PGLs are considered to pose some risk of metastasis, and long-term follow-up is advised.

November 2004: intradural mass of the cauda equina in a woman in her early 60s

November 2004. A 63-year-old woman presented with slowly aggravating lower back pain and recent urinary urge incontinence. MRI revealed a sharply-delineated, partly cystic intradural mass with inhomogenous contrast-enhancement and ectatic vessels at the upper pole. An ependymoma was suspected, and the tumor was resected in toto. Histologically, at first glance, the tumor strongly resembled an ependymoma, showing a monomorphic cellular pattern, perivascular pseudorosettes and ependymal canal-like structures. However, the finding of a delicate collagen capsule, compartmentation of tumor cells into zellballen and the presence of ganglionic cells were untypical. These features were indicative of a paraganglioma with a gangliocytic component. Immunoreactivity of the tumor cells for neuroendocrine antigens, the detection of GFAP-positive sustentacular cells and the ultrastructural confirmation of neurosecretory granules substantiated this diagnosis. The clinical, radiological and morphological similarity between ependymomas, which are far more common in the cauda equina region than paragangliomas, has led to substantial diagnostic confusion in the past.

Paragangliomas of the lumbar region

✓ The author reports two cases of cauda equina paraganglioma (CEP) and provides a review of all previously published cases. The current radiological, neurosurgical, and pathological literature on this rare tumor is also reviewed.

Cerebellar paraganglioma

Paragangliomas arising as primary neoplasms in the intracranial portion of the central nervous system are relatively uncommon and only have been rarely reported. We report a case of apparent primary paraganglioma arising in the left cerebellar hemisphere in an 11-year-old girl who presented with a 6-month history of headaches. The tumor was marked by a nested architectural pattern (zellballen), delimited by S-100-positive sustentacular cells. Morphologic and immunohistochemical features of the neoplasm are discussed and literature is reviewed regarding involvement of the central nervous system by paraganglioma.

Pigmented papillary epithelial neoplasm of the pituitary fossa: a distinct lesion of uncertain histogenesis

Primary pigmented intracranial neoplasms are strikingly uncommon. The differential diagnosis is limited and includes both epithelial and nonepithelial tumors, most of which arise within or near the ventricular system. The authors describe a 42-year-old man who presented with a pigmented papillary epithelial lesion that arose within the sella and exhibited suprasellar extension and bony erosion. Following external beam radiotherapy and multiple surgical resections, tumor growth became rapid, necessitating additional debulking procedures. Pathologic evaluation of subsequent lesional tissue samples revealed an anaplastic lesion with malignant epithelial and spindle cell components. Occasional epithelial cells showed features reminiscent of the original papillary lesion, whereas others exhibited oncocytic morphologic features. This case represents the only report, to our knowledge, of a pigmented papillary epithelial neoplasm arising within the pituitary fossa. Although the histogenesis of this tumor is enigmatic, this appears to be a distinct lesion characterized by aggressive growth and the capacity for anaplastic progression.

Choroid plexus papilloma: a clinicopathological study of 23 cases

BACKGROUND

Choroid plexus papillomas (CPPs) are rare, accounting for less than 1% of all intracranial tumors in adults. However, they are relatively more common in childhood and constitute 1.5 to 4% of intracranial tumors.

DESCRIPTION

They are most often located in the lateral ventricle, followed by the fourth and third ventricles and, rarely, in the cerebellopontine angle. The radiological appearance of a CPP as a cyst with a mural nodule is a curiosity. Bone formation is rare in CPPs and only 6 cases have been described in the literature. Neuromelanin production is also extremely rare and only 2 cases have been reported to date.

CONCLUSION

In the present communication, 23 cases of CPP are analyzed and rare clinical, pathological, and radiological features are described.

Giant cell ependymoma of the filum terminale. A report of two cases

We describe two histologically unusual cases of ependymoma of the filum terminale. Both tumors occurred in 14-year-old boys. An intradural encapsulated mass attached to the filum terminale was demonstrated radiologically in both cases and totally resected at surgery. In case 1 the neoplasm was uniformly composed of pleomorphic giant cells and was without perivascular pseudorosettes or myxopapillary changes. Case 2 was a myxopapillary ependymoma with multiple foci of pleomorphic giant cells. Neither tumor had prominent mitotic activity, necrosis, or endothelial proliferation. Both tumors were immunopositive for cytokeratin and glial fibrillary acidic protein. Ultrastructural features included basal laminae, interdigitating cell processes, microvilli, cilia, intercellular junctions, and cytoplasmic intermediate filaments. Cytogenetic analysis in case 1 showed a hypodiploid karyotype with monosomy of chromosomes 1, 10, 14, 16, 20, and 22. We interpret both tumors as most consistent with a variant of ependymoma. Because of the unique gigantocellular light microscopic appearance of the entire tumor in case 1, we propose classifying this tumor as a new morphologic subtype: giant cell ependymoma of the filum terminale. The combination of gigantocellular and myxopapillary features in case 2 supports a histogenetic relationship between giant cell ependymoma and myxopapillary ependymoma.

Mixed ependymoma-neuroendocrine tumor of the lateral ventricle

A histologically unique glioneuronal neoplasm occupying the lateral ventricle of a child was immunohistochemically and ultrastructurally characterized. Its principal component exhibited the characteristic features of ependymoma, whereas a minor population of neuroendocrine cells, occurring singly and in small clusters, lay scattered throughout the ependymoma component. Yet another unusual finding was the presence of numerous elastic fibers within the extracellular matrix. This tumor is considered to represent a true mixed neoplasm consisting of ependymal and neuroendocrine elements.