Tanycytic ependymoma arising from the right lateral ventricle: a case report and review of the literature

Whorling Sclerosing Ependymoma of the Cervical Spinal Cord Presenting Tanycytic Histopathologic Features: A Rare Case Report

Tanycytic ependymoma is a neuroectodermal tumor that arises from ependymoglial cells or tanycytes. It is highly uncommon. We reported a 34-year-old man who was diagnosed with intradural-intramedullary tanycytic ependymoma, located at the level of C4-5 who had a 9-months history of neck pain and left arm pain, and numbness on fingers. One month prior to presentation, his left arm numbness and paresthesia deteriorated. The lesion was removed totally by C4, C5 hemilaminoplasty. The histologic pattern of this lesion was consisted of fascicles forming nebula-like whorling structures. Because of these structures, tanycytic ependymoma should be taken into consideration in the differential diagnosis of a whorling-sclerosing variant of meningiomas.

An Insight into Pathophysiological Features and Therapeutic Advances on Ependymoma

Simple Summary

Although biological information and the molecular classification of ependymoma have been studied, the treatment systems for ependymoma are still insufficient. In addition, because the disease occurs infrequently, it is difficult to obtain sufficient data to conduct large-scale or randomized clinical trials. Therefore, this study is intended to emphasize the importance of understanding its pathological characteristics and prognosis as well as developing treatments for ependymoma through multilateral studies.

Abstract

Glial cells comprise the non-sensory parts of the central nervous system as well as the peripheral nervous system. Glial cells, also known as neuroglia, constitute a significant portion of the mammalian nervous system and can be viewed simply as a matrix of neural cells. Despite being the “Nervenkitt” or “glue of the nerves”, they aptly serve multiple roles, including neuron repair, myelin sheath formation, and cerebrospinal fluid circulation. Ependymal cells are one of four kinds of glial cells that exert distinct functions. Tumorigenesis of a glial cell is termed a glioma, and in the case of an ependymal cell, it is called an ependymoma. Among the various gliomas, an ependymoma in children is one of the more challenging brain tumors to cure. Children are afflicted more severely by ependymal tumors than adults. It has appeared from several surveys that ependymoma comprises approximately six to ten percent of all tumors in children. Presently, the surgical removal of the tumor is considered a standard treatment for ependymomas. It has been conspicuously evident that a combination of irradiation therapy and surgery is much more efficacious in treating ependymomas. The main purpose of this review is to present the importance of both a deep understanding and ongoing research into histopathological features and prognoses of ependymomas to ensure that effective diagnostic methods and treatments can be developed.

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.

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.

Cerebellar ependymoma with overlapping features of clear-cell and tanycytic variants mimicking hemangioblastoma: a case report and literature review

BACKGROUND

Imaging and histology of clear-cell ependymoma and cerebellum-based hemangioblastoma are similar; distinguishing between them is a diagnostic challenge.

CASE PRESENTATION

A 62-year-old Chinese woman presented with an intermittent headache of 8 years' duration. Computed tomography and magnetic resonance imaging revealed a mass in the cerebellum. Neurological imaging suggested hemangioblastoma (HB). Histologically, the tumor included cellular and paucicellular areas, in which cells were arranged in nests or diffusely distributed; and a highly vascular area, in which tumor cells were arranged in clusters and separated by capillaries. At low magnification, the tumor mimicked cellular HB, but at high magnification, tumor cells showed clear cytoplasm instead of the vacuolated cytoplasm typically observed in HB. Moreover, spindly, bipolar elements resembling tanycytes were observed within the nest structures. Although these features indicated the possibility of ependymoma, neither true ependymal rosettes nor an ependymal-lined profile was observed. The tumor was characterized by prominent vascularity, but glomeruloid formation was absent. We saw pleomorphism in foci of some tumor giant cells, but pathologic mitosis and palisaded necrosis were absent. Most tumor cells were positive for glial fibrillary acidic protein and S100. Epithelial membrane antigen was expressed with a paranuclear dot-like or a ring-like pattern. The Ki-67 index was approximately 2%. Considering the patient's symptom, neurological imaging, and pathological findings, she was diagnosed as cerebellar ependymoma (WHO grade II).

CONCLUSIONS

Here, we report a case of ependymoma with overlapping clear-cell and tanycytic features, and review the literature to evaluate its real incidence. Pathologists should consider this rare diagnosis when confronted with a similar presentation.

Spinal cord ependymoma: a review of the literature and case series of ten patients

Spinal cord ependymoma (SCE) is a rare tumor that is most commonly low-grade. Complete surgical resection has been established as first-line treatment and can be curative. However, SCEs tend to recur when complete tumor resection is not possible. Evidence supporting the use of adjuvant radiation and chemotherapy is not definitive. We review the most recent literature on SCE covering a comprehensive range of topics spanning the biology, presentation, clinical management, and outcomes. In addition, we present a case series of ten SCE patients with the goal of contributing to existing knowledge of this rare disease.

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.

A 40-year-old male with an intraventricular tumor. Combined tanycytic ependymoma and subependymoma

Combined tumors showing histologic features of both ependymoma and subependymoma have been described. In this report we present a case of combined tanycytic ependymoma with foci of subependymoma (WHO grade II), occurring in a 40 year-old male, which arose in the wall of the lateral ventricle. The tanycytic ependymoma component showed elongated fibrillary cells with a fascicular pattern of growth, while the subependymoma component showed clustered cell bodies surrounded by a fibrillary stroma with a microcystic appearance.We consider the present case to be an unusual example of tanycytic ependymoma; which to the best of our knowledge has not been associated with a subependymoma.

Spinal tanycytic ependymoma with diffusion restriction on MRI

Tanycytic ependymoma is a rare spindle-cell variant of ependymoma derived from tanycytes. Primitive neuroectodermal tumors usually have diffusion restriction, whereas ependymomas do not. Here, we present a case of tanycytic ependymoma with diffusion restriction. As far we are aware, this is the first case of tanycytic ependymoma in the English literature with diffusion restriction.

Extradural nodular fasciitis arising in the spinal canal

STUDY DESIGN

Case report.

OBJECTIVE

To describe a patient with nodular fasciitis arising in the lumbar extradural space.

SUMMARY OF BACKGROUND DATA

Nodular fasciitis is a benign proliferation of fibroblasts and myofibroblasts. It commonly occurs in the subcutaneous tissue of an upper extremity, trunk, head, and neck, but rarely arises in the spinal canal.

METHODS

A 7-year-old boy experienced gradually increasing intense radiating pain from the bilateral buttocks to the lower extremities after a bruise on his lower back. Computed tomography and magnetic resonance imaging demonstrated a relatively circumscribed mass in the dorsal epidural space from the first lumbar vertebra (L1) to L2. The presumptive diagnosis based on the radiologic findings included aggressive neoplasm such as extraskeletal Ewing sarcoma/primitive neuroectodermal tumor or malignant lymphoma.

RESULTS

The patient underwent L1-L2 laminectomy and resection of the tumor. Histologically, the tumor was mainly composed of a proliferation of spindle cells without atypia, positive for vimentin and smooth muscle actin, and myxoid areas with a loosely textured feathery pattern. These findings are the typical features of nodular fasciitis. Surgery relieved the patient's pain, with no evidence of recurrence at a recent 4-year follow-up.

CONCLUSION

This report presents a very rare case of extradural nodular fasciitis arising in the lumbar spinal canal, which could have been misinterpreted as a malignant tumor such as extraskeletal Ewing sarcoma/primitive neuroectodermal tumor because of its rapid growth and absence of distinguishing radiologic features. A detailed histopathologic examination including immunohistochemistry is important for the correct diagnosis.