Tanycytic ependymoma of the filum terminale with pleomorphic giant cells

A case of myxopapillary ependymoma with predominant giant cell morphology: A rare entity with comprehensive genomic profiling and review of literature

In the evolving landscape of ependymoma classification, which integrates histological, molecular, and anatomical context, we detail a rare case divergent from the usual histopathological spectrum. We present the case of a 37-year-old man with symptomatic spinal cord compression at the L3-L4 level. Neuroradiological evaluation revealed an intradural, encapsulated mass. Histologically, the tumor displayed atypical features: bizarre pleomorphic giant cells, intranuclear inclusions, mitotic activity, and a profusion of eosinophilic cytoplasm with hyalinized vessels, deviating from the characteristic perivascular pseudorosettes or myxopapillary patterns. Immunohistochemical staining bolstered this divergence, marking the tumor cells positive for glial fibrillary acidic protein and epithelial membrane antigen with a characteristic ring-like pattern, and CD99 but negative for Olig-2. These markers, alongside methylation profiling, facilitated its classification as a myxopapillary ependymoma (MPE), despite the atypical histologic features. This profile underscores the necessity of a multifaceted diagnostic process, especially when histological presentation is uncommon, confirming the critical role of immunohistochemistry and molecular diagnostics in classifying morphologically ambiguous ependymomas and exemplifying the histological diversity within MPEs.

Giant Cell-rich Tanycytic Ependymoma as Intramedullary Spinal Mass

Intramedullary spinal cord tumors are rare neoplasms and harbour full spectrum of primary neoplasms as seen within the intracranial compartment. They include tumors with diverse pathologies, arising in both adults and children and pose considerable diagnostic challenge. The differentials at this site include wide ranging pathologies from benign, circumscribed pilocytic to diffuse astrocytoma, myxopapillary or tanycytic ependymoma and malignant diffuse midline glioma. Rare instances of glioneuronal tumors, pleomorphic xanthoastrocytoma have also been described at this location. H3K27M mutant diffuse midline high grade glioma is the new entry to this list in 2016 updated WHO classification. We describe the morphologic features of a diagnostically challenging intramedullary spinal cord tumor masquerading as a high grade lesion due its cellular composition and discuss its differentials. The report also emphasizes the role of already established and recently introduced immunohistochemical markers and other ancillary techniques as useful adjuncts in the diagnosis.

Tanycytic ependymoma of filum terminale: Clinical characteristics and surgical outcomes

Tanycytic ependymoma (TE), a rare subtype of ependymoma, was classified as grade II ependymoma by the World Health Organization in 2000 and 2007. Preoperative diagnosis of TE is challenging due to its similarities to schwannoma and astrocytoma; therefore, differentiation is required. The present study investigated the clinical, imaging and pathological characteristics of TE in the filum terminale. A retrospective analysis was conducted on the clinical, imaging, pathological and immunohistochemical characteristics of 8 patients with TE in the filum terminale and the relevant literature was reviewed. Of the 8 patients 7 were female and 1 was male, with an age range of 24–62 years old. The primary clinical symptom observed was lumbago, accompanied by lower limb pain and numbness. Magnetic resonance imaging predominantly identified isointensity on thoracic (T) 1-weighted images and iso- or hyperintense signal intensity on T2-weighted images, with homogeneous or inhomogeneous enhancement. All patients underwent resection of the tumor through a posterior median approach, and total resection was acighieved in 7 patients. During postoperative follow-up, all patients experienced improvement compared with their preoperative status, and were without tumor recurrence. The present study comprised the largest group of cases with TE in the filum terminale reported so far, to the best of our knowledge, which could foster a better understanding of this disease. Complete surgical resection of the tumor has the greatest effectiveness of any treatment for TE in the filum terminale. Postoperative histological examination, immunohistochemistry and electron microscopy for tumor specimens may assist in its diagnosis and differential diagnosis.

Tanycytic Ependymoma of the Filum Terminale Region; a Case Report

Tanycytic ependymoma is a very rare spindle-cell variant of ependymoma derived from tanycytes, which are part of the primitive nervous system. This paper is presenting 48-year old woman who presented with low back and right-sided leg pain of moderate intensity. MRI showed spinal intradural tumor at the level of the L1 vertebral body. Right-sided L1 hemilaminectomy and en bloc tumor resection were performed. Neuroradiological and intraoperative diagnosis of schwannoma was revised to tanycytic ependymoma after careful immunohistochemical analysis. Six months post-operativly, MRI did not show tumor recurrence. Tanycytic ependymoma at the region of filum terminale is extremely uncommon and only three cases have been described in the literature. The low incidence of this tumor and atypical histological image, which is distinct from the typical features of commonly encountered ependymomas, can present a challenge in terms of making an accurate diagnosis. Awareness of this transitional form of ependymoma among neurosurgeons and pathologists may avoid incorrect surgical approaches and postoperative treatment course.

The Clinical Features and Surgical Outcomes of Spinal Cord Tanycytic Ependymomas: A Report of 40 Cases

OBJECTIVE

Spinal cord tanycytic ependymomas (TEs) rarely are reported because of extremely low incidence. Understanding of this disease is therefore poor. The aim of this study was to analyze the incidence and clinical, radiologic, pathologic, and prognostic features of spinal cord TEs.

METHODS

Approximately 4000 spinal cord tumors were resected surgically in Beijing Tiantan Hospital between April 2009 and May 2016. We identified all cases of pathologically proved TEs among these patients.

RESULTS

TEs accounted for approximately 1% of spinal cord tumors (40 of an estimated 4000). Patients with TE were a mean age of 40.0 years and had no significant sex preference (21 male and 19 female). The median diameter of the maximal tumor was 54.2 mm (range, 16-153 mm). The mean preoperative Japanese Orthopedic Association (JOA) score was 13.0. Radiologically, 47.5% (19/40) cases showed poorly defined tumor border, and 40% (16/40) of them showed preoperative syringomyelia. Gross total resection was achieved in 30 cases, subtotal resection in 8, and partial resection in 2. At the time of discharge, JOA score and neurologic function showed improvement in 26 cases (65%), no change in 12 cases (30%), and worsening in 2 cases (5%). At a median follow-up of 43 months (range, 7-101 months), 1- and 5-year progression-free survival rates were 100.0% and 97.5%, respectively. Only one patient had tumor recurrence which was found 30 months after surgery. No patient died of tumor recurrence. At the latest follow-up, JOA score showed improvement in 30 cases (75%), no change in 8 cases (20%), and worsening in 2 cases (5%). Univariate analysis revealed that tumor size and preoperative JOA score were significantly associated with the short-term outcomes. Meanwhile, age ≥40 years, tumor size ≥50 mm, non-gross total resection, and preoperative JOA score <14 were significantly associated with an increased risk of worsened long-term outcomes. Poorly defined tumor border and preoperative JOA score <14 significantly limited the extent of tumor resection.

CONCLUSIONS

Spinal cord TE is a rare subtype of ependymomas with low recurrence. Long-term survival can be expected, although poorly defined tumor border is an independent predictor of long-term outcomes. Microsurgical treatment of spinal cord TEs remains a formidable challenge due to the poorly defined border and critical neurovascular structures encasement. It is unnecessary for radical tumor resection at the cost of severe neurologic deficits.

Immunohistochemical features of giant cell ependymoma of the filum terminale with unusual clinical and radiological presentation

BACKGROUND

Giant cell ependymoma of the filum terminale is a rare variant, generally manifested as a well-circunscribed intradural mass with an indolent biological behavior.

CASE PRESENTATION

We describe the case of a 48-year-old Mexican female who non-relevant past medical history, that developed a GCE of the filum terminale. Magnetic resonance imaging and computed tomography revealed the presence of an intra-axial tumor extending from L3 to L5 with extra-medullary invasion. Therefore the tumor was considered unresectable and only incisional biopsy was obtained, establishing the tentative diagnosis of a poorly differentiated neoplasia. A second evaluation of the case revealed the presence of numerous non-cohesive pleomorphic giant cells with intranuclear inclusions and broad eosinophilic cytoplasm, alternating with intermediate size cells with round, hyperchromatic nuclei and forming a perivascular pseudo-rosettes pattern. The ependymal phenotype was supported by light microscopy and corroborated by immunohistochemistry analysis. The patient was subsequently treated with radiotherapy 54Gy. She is alive after a 27-month follow-up, with residual disease, difficulty ambulating and pain.

CONCLUSIONS

GCE of filum terminale may have an atypical clinical and radiological presentation, albeit with invasive characteristics and anaplasia on histologic analysis. However, its biological behavior is indolent and associated to longer survival. Due to the presence of giant cells, the differential diagnosis of other primary neoplasias at that site were considered, including paraganglioma, malignant peripheral nerve sheath tumors as well as metastatic malignant melanoma, adrenal carcinoma, thyroid gland carcinoma and urothelial carcinoma, that may all harbor giant cells.

Imaging features of spinal tanycytic ependymoma

Tanycytic ependymoma is an unusual morphological variant of WHO grade II ependymoma, typically arising from the cervical or thoracic spinal cord. Although the literature deals extensively with pathological features of this tumour entity, imaging features have not been well characterised. The purpose of this study was to review magnetic resonance imaging (MRI) features of spinal tanycytic ependymomas reported in the literature to date, exemplified by a case of a patient with tanycytic ependymoma of the conus medullaris presenting to our hospital. A Medline search of the English literature for all previously published cases of spinal tanycytic ependymoma was carried out and the reported MRI features reviewed. The tumours were found to be typically well-demarcated masses, predominantly showing isointensity on T1-weighted signal, and T2-weighted hyperintensity, with variable patterns of contrast enhancement. A cystic component was seen in half of the cases, and in a minority a mural nodule was present within the cyst wall. Associated syrinx formation was observed in one-third of the cases and haemorrhage was rare, which may be helpful pointers in differentiating the lesion from other ependymoma subtypes. In conclusion, MRI characteristics of spinal tanycytic ependymoma are variable and non-specific, and radiological diagnosis thus remains challenging, although certain predominant features are identified in this report. Knowledge of these is important in the diagnostic differentiation from other intramedullary and extramedullary spinal tumours in order to guide appropriate surgical management.

Tanycytic ependymoma of the filum terminale associated with multiple endocrine neoplasia type 1: first reported case

BACKGROUND CONTEXT

Ependymoma associated with multiple endocrine neoplasia type 1 (MEN-1) is an extremely rare clinical entity. To the best of our knowledge, only five cases of ependymoma associated with MEN-1 have been previously described. Furthermore, there has been no case of tanycytic ependymoma of the filum terminale associated with MEN-1.

PURPOSE

The present case report illustrates a 53-year-old man with tanycytic ependymoma of the filum terminale associated with MEN-1. We review the literature on ependymoma with MEN-1 and tanycytic ependymoma of the cauda equina region and also discuss the risk of recurrence.

STUDY DESIGN

A case report.

METHODS

The patient presented with complaints of nocturnal pain in the lower back, accompanied by numbness around the anus and intermittent claudication for approximately 1 year. Magnetic resonance imaging (MRI) identified an intradural-enhancing, large mass lesion at the level from Th12 to L2 vertebrae, with a cranial cystic lesion.

RESULTS

Open-door laminoplasty of the Th12, L1, and L2 and en bloc tumor resection with thickened filum terminale were performed. Histopathologic examination of the tumor specimens showed tanycytic ependymoma (World Health Organization Classification Grade II). At the time of the 2-year and 8-month follow-up examination, MRI did not show tumor recurrence.

CONCLUSIONS

This is the first reported case of this clinical entity. A careful follow-up of patients with this unusual tumor is strongly recommended.

Cytologic features of giant cell ependymoma: a case report and review of the literature

Here, we present a case of anaplastic giant cell ependymoma (GCE) occurring in a 15-year-old woman. Squash smear slides for intraoperative frozen section diagnosis revealed oval to round cell clusters with a papillary structure in a fibrillary background. This was occasionally accompanied by the presence of bizarre pleomorphic giant cells with hyperchromatic nuclei and prominent intranuclear inclusions. These intranuclear inclusions were a key clue to diagnosis of ependymoma. Histologic analysis revealed features of a high-grade tumor with perivascular pseudorosettes and bizarre pleomorphic giant cells, which established the diagnosis of GCE. We performed a review of literatures about the cytologic features of GCE, including our case, thus proposing that intraoperative frozen diagnosis of GCE would be established by squash smear preparations featuring the mitosis and necrosis, as well as the high cellularity, and the presence of giant cells showing hyperchromatic nuclei with eosinophilic cytoplasm and intranuclear inclusions/pseudoinclusions.

Giant cell ependymoma of the thoracic spinal cord

We report a new case of giant cell ependymoma (GCE) of the thoracic spinal cord. Ependymomas predominate in children and young adults and are frequently intracranial and infra-tentorial. However, a second age peak at 30-40 years is reported for spinal tumours. Microscopically, ependymomas show a large variety of histological features, among which a rare variant with giant cells. This 59-year-old woman presented with a 6-month history of numbness and burning sensation affecting the left lower limb and hemi-trunk. A cervico-thoracic MRI revealed a solid intra-medullary tumour at the level of T1-T3, slightly T1-hypointense, T2-hyperintense and contrast enhancing. A complete surgical resection was carried out through a C7 to T4 laminectomy. Recovery was complete with no sign of recurrence at 18-month follow-up. The initial histological diagnosis of glioblastoma was challenged on the basis of the imaging and operative findings of a well-circumscribed tumour. The case was sent to us for second opinion and we diagnosed a GCE, WHO grade II, with a biphasic pattern including a predominant giant cell component (>90%), with genetic evidence of polyploidy, and a very limited classic component, showing a characteristic loss of chromosome 22. Our report adds to the clinical, imaging, pathological and genetic characterisation of GCE and brings the first genetic evidence that these rare tumours are at least bi-clonal. It also suggests that GCE have a good prognosis after complete surgical resection.