Light microscopic demonstration of the microlumen of ependymoma: A study of the usefulness of antigen retrieval for epithelial membrane antigen (EMA) immunostaining

Benign Spinal Tumors

Benign spinal intradural tumors are relatively rare and include intramedullary tumors with a favorable histology such as low-grade astrocytomas and ependymomas, as well as intradural extramedullary tumors such as meningiomas and schwannomas. The effect on the neural tissue is usually a combination of mass effect and neuronal involvement in cases of infiltrative tumors. The new understanding of molecular profiling of different tumors allowed us to better define central nervous system tumors and tailor treatment accordingly. The mainstay of management of many intradural spinal tumors is maximal safe surgical resection. This goal is more achievable with intradural extramedullary tumors; yet, with a meticulous surgical approach, many of the intramedullary tumors are amenable for safe gross-total or near-total resection. The nature of these tumors is benign; hence, a different way to measure outcome success is pursued and usually depends on functional rather than oncological or survival outcomes.

Cerebral astroblastoma with oligodendroglial-like cells: A case report

RATIONALE

Astroblastoma is a rare tumor of the central nervous system with uncertain biological behavior and origin. Its histopathological features have been well established, while, to our knowledge, astroblastoma with oligodendroglial-like cells have not been reported.

PATIENT CONCERNS

A 15-year-old girl presented with nausea, vomiting, headache, and visual disturbance.

DIAGNOSIS

Magnetic resonance imaging revealed a large neoplasm in the left temporal. Histologically, the tumor showed solid and pseudopapillary structure. Immunohistochemical staining showed that the tumor cells were positive for glial fibrillary acidic protein and vimentin. The oligodendroglial-like cells were positive for glial fibrillary acidic protein, vimentin, and oligodendrocyte transcription factor 2. The antigen KI67 labeling index was about 4%. Sequencing for isocitrate dehydrogenase (IDH) 1 codon 132 and IDH2 codon 172 gene mutations showed negative results. Furthermore, fluorescent analysis revealed neither 1p nor 19q deletion in the lesion. Based on these findings, the girl was finally diagnosed as astroblastoma.

INTERVENTIONS

A craniotomy with total excision of the tumor was performed.

OUTCOMES

The follow-up time was 1 year, no evidence of disease recurrence was found in magnetic resonance imaging.

LESSONS

Cerebral astroblastoma with oligodendroglial-like cells is a clinically rare tumor of central nervous system. Clear distinction and diagnosis are critical.

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.

A case of multinodular high-grade neuroepithelial tumor with ependymal differentiation

We describe a rare case of multinodular cerebral neuroepithelial tumor with ependymal differentiation. A 65-year-old man experienced loss of consciousness with an obscure episode of seizure attack. Magnetic resonance images disclosed a lesion located in the left temporal lobe and the insular cortex. The tumor was partially removed. Histologically, the tumor showed infiltrating multinodular tumor nodules in the cerebrum. Each nodule was well demarcated and composed of clear cells with perinuclear halos, intermingled fibrillary cells, and poorly differentiated neuroepithelial cells with mitotic activity. Immunohistochemically, clear cells showed dot-like positivity for epithelial membrane antigen. Fibrillary cells were positive for vimentin and nestin, whereas only a few glial fibrillary acidic protein-immunopositive cells were seen. We conclude that this tumor, being microscopically characterized by multinodular tumor nodules, was a high-grade neuroepithelial tumor with ependymal differentiation.

Tanycytic ependymoma of the spinal cord with anaplastic cytological features

In a 43-year-old man, an intramedullary spinal cord tumor spreading from the level of the T2 to T5 vertebrae was subtotally resected. The tumor predominantly consisted of a fascicular proliferation of spindle cells having bland nuclei and bipolar, long cytoplasmic processes, and a few perivascular pseudo-rosettes were found. Although there were no true ependymal rosettes, intracytoplasmic dot-like immunoreactivity for epithelial membrane antigen (EMA) was found in a few cells. In some areas, a dense and diffuse proliferation of anaplastic, short-spindled cells having hyperchromatic nuclei and scant cytoplasm was noted, and the Ki-67 labeling index was remarkably higher (18.2%) in these areas. Neither microvascular proliferation nor necrosis was observed. In the boundary region, these two areas showed gradual transition from one to the other. The patient has remained free from recurrence for 10 months postoperatively. This is the first documentation of tanycytic ependymoma in which tumor cells showed anaplastic cytological features.

Patterns of brain infiltration and secondary structure formation in supratentorial ependymal tumors

Ependymomas are generally considered to be noninfiltrative tumors that have discrete borders with adjacent brain tissue. Most occur in the posterior fossa or spinal cord. Supratentorial ependymal tumors arise near the ventricular system or, more rarely, within the cerebral white matter or cortex. Presented here are 6 supratentorial ependymal tumors, 3 that primarily involve the cerebral cortex and 3 that extend into the cortex from the underlying white matter. By microscopy, all of these tumors locally infiltrate the cortex and/or white matter along small blood vessels and axonal fiber tracts. They also form other glioma secondary structures including perineuronal tumor cell satellitosis and subpial tumor cell mounds. The 3 cortical ependymal tumors show a spectrum of features ranging from conventional and clear-cell ependymoma-like patterns to more angiocentric glioma-like histology. Because ependymal tumors generally have a significantly better prognosis than other infiltrating gliomas, recognition of their capacity to infiltrate adjacent cortex and white matter is important to prevent the misdiagnosis of oligodendroglioma, astrocytoma, or infiltrating glioma, not otherwise specified. Cortical ependymomas and angiocentric gliomas may comprise a group of locally infiltrative ependymal tumors that are associated with an excellent prognosis after gross total surgical resection.

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

A 38-year-old man presented with a year-long history of worsening headache. Neuroradiological findings showed that a solid cystic mass occupied the right lateral ventricle. Histologically, the tumor composed of nuclear dense zones consisting of a cluster of spindle cells and fibrillary zones consisting of streaming of cell processes. The tumor cells showed the characteristics of monopolar or bipolar processes. Some tumor cell processes extended to the vessel wall and formed ill-defined perivascular rosettes. No mitoses or necrosis were found. The cells presented positive for GFAP, S-100 protein, vimentin, Nestin and neurofilament, and dotlike positive for epithelial membrane antigen, but negative for Syn and NeuN. Four cases of tanycytic ependymoma arising from the lateral ventricle have been reported in literature. Histological differential diagnosis includes spindle-shaped neuroepithelial tumors, such as pilocytic astrocytoma, fibrillary astrocytoma and schwannoma. Tanycytic ependymoma has slightly better prognosis than other ependymoma subtypes.

Épendymomes intracrâniens de l'adulte. Diagnostic histologique et facteurs histopronostiques

BACKGROUND

Intracranial ependymomas are rare in adults and histopathological prognostic factors are poorly determined.

PURPOSE

A retrospective multicentric study was conducted in France in order to assess the prognostic value of histology.

MATERIAL

Between 1990 and 2004, 216 adult patients with newly diagnosed ependymomas were treated in 19 French centers. Eligibility required institutional histopathological confirmation of an ependymoma and available clinical history and MRI features (see comparison paper).

METHODS

Histological preparations and one paraffin embedded block from each patient were sent to Pr D. Figarella-Branger in Marseille. Central review by four neuropathologists (D. Figarella-Branger, A. Maues de Paula, C. Fernandez and A. Jouvet) was performed. Specimens for which all pathologists agreed with the histological diagnosis of ependymomas were included, whereas cases for which all disagree were excluded and reclassified. In the event of doubt and/or discrepancies between pathologists immunostaining was performed in order to reach a consensus diagnosis. Diagnostic of ependymomas was confirmed in 121 cases (56%). In theses cases, ependymomas were classified according to the WHO system (subtype and grade). The potential prognostic value (overall survival OS and disease free survival DFS) of the following histological parameters was examined: perivascular pseudorosettes, ependymal rosettes, hyalinized vessels, mitotic index, microvascular proliferation, necrosis, area of increased cellularity, nuclear atypia, brain invasion and Mib-1 labelling index.

RESULTS

Among the 121 ependymomas, 88 were grade II (47 classic, 17 cellular, 2 papillar, 6 clear cells and 16 tanicytic) and 33 grade III. WHO grading, occurrence of microvascular proliferation, necrosis, nuclear atypia and high proliferative index were correlated with both OS and DFS. Moreover, quantification of certain parameters enabled a reproducible grading system correlated with both OS and DFS.

Podoplanin is expressed in subsets of tumors of the central nervous system

Immunohistochemical analyses with the monoclonal antibody D2-40 were performed to ascertain the expression of podoplanin (a.k.a. T1-alpha, gp36, or aggrus) in tumors of the central nervous system (CNS) and to determine the diagnostic utility of the antibody. The analyses were performed on 325 tumors of various histologic types. The chief finding was almost constant immunoreactivity in ependymal tumors (37/40, 92.5%), choroid plexus papillomas (8/8, 100%), and meningiomas (100/100, 100%). The reactivity was considered "tissue-specific," as the corresponding normal tissue of each tumor was also found to express podoplanin. In addition, expression, not committed to the lineages, was found in many other tumor types, including astrocytic tumors, medulloblastomas, and hemangioblastomas, with variable frequency and intensity. The way of expression was not fully understood, but the expression in astrocytic tumors seemed to be associated with pronounced fibrous properties or malignant phenotype, as was shown by high-frequent expression in pilocytic astrocytomas (12/12, 100%) and glioblastomas (29/35, 82.9%). The present study has shown that podoplanin is expressed in several types of CNS tumors with variable frequency and intensity. Given the widespread expression of podoplanin, the antibody D2-40 is of little use in diagnostic practice for CNS tumors.

Atypical extraventricular neurocytoma

Extraventricular neurocytoma (EVN) is a rare brain tumor that poses diagnostic difficulty. Described herein is a case of atypical EVN arising in a 54-year-old woman. A well-circumscribed lesion (3.0 x 3.0 x 3.0 cm) in the right parietal lobe showed diffuse proliferation of monotonous tumor cells with perinuclear clearing within a delicate fibrillary matrix similar to neuropil. Tumor also showed vascular proliferation and high mitotic activity. Immunohistochemically, these tumor cells were strongly positive for synaptophysin both in the neuropil and in the perinuclear cytoplasm, and were negative for glial fibrillary acidic protein and Olig2. Ki-67 labeling index was 13.0% in the most stained areas, but accumulation of p53 was not observed. These findings were compatible with those of EVN with histological atypia. EVN should be considered as a candidate in the differential diagnosis of parenchymal brain tumor, especially oligodendroglioma. The important features are the delicate fibrillary matrix similar to neuropil, diffuse and strong immunoreactivity for synaptophysin, and negative immunoreactivity for Olig2. High proliferative activity without accumulation of p53 suggests that other factors are involved in oncogenesis of atypical EVN.