Glioneurocytoma: tumor with glial and neuronal differentiation

Psychiatric symptoms in children with low-grade glioma and craniopharyngioma: A systematic review

The presentation of psychiatric symptoms in pediatric low-grade brain tumors is challenging because this can delay proper diagnosis and treatment. We performed a systematic review of psychiatric presenting symptoms of low-grade brain tumors in pediatric patients. We searched the PubMed and Web of Science databases of studies published in English from 1977 until 2019 reporting patients aged ≤21 years at the time of tumor diagnosis who exhibited psychiatric/behavioral symptoms before diagnosis of low-grade glioma (LGG), pilocytic astrocytoma (PA), or craniopharyngioma (CP). Our systematic search strategy coupled each tumor type with patient age and presenting symptoms by using different variations of the search terms "childhood" and "psychiatric symptoms" or "behavioral symptoms." We identified six unique articles that met our inclusion criteria in the LGG search, 27 in the PA search, and 32 in the CP search. Six patients were included in the LGG articles (age range, 3-16 years), 75 in the PA articles (age range, 0.5-21 years), and 87 in the CP articles (age range, 0.67-21 years). The most common presenting symptoms included eating disorders (n = 64) and behavioral changes (n = 49). Our findings demonstrate the need to establish clear criteria for neuroimaging indications for pediatric patients exhibiting eating disorders.

Hemispheric extra-ventricular glioneurocytoma: a clinicopathological review with detailed immunohistochemical profile

Glioneuronal tumors have recently been recognized in the WHO Classification of Tumors of the Central Nervous System, 2007 [14]. However, the entities included in this category do not encompass all the glioneuronal tumors encountered during practice. We characterize a new entity called glioneurocytoma (GNC) showing distinct morphology with glial and neuronal differentiation. We reviewed 10 cases of glioneurocytomas diagnosed in our department during 2003 and 2004, with emphasis on clinicopathological features, immunohistochemical profile, genetic aberrations and prognosis. The cases included in the study showed equal gender distribution and age range of 23-40 years and mean age of 34.4 years at the time of initial presentation. Most of the tumors were centered in the frontal lobe. In our study, GFAP was the most sensitive and relatively specific marker for glial differentiation and remains the marker of choice for glial differentiation. CD56 and S100 protein were sensitive but non-specific. Vimentin, CD57 and NF were non-contributory in the immunohistochemical work up of glioneurocytomas. We concluded that the diagnosis of glioneurocytomas requires attention to morphological details and proper immunohistochemical assessment, using a panel of both glial and neuronal markers. Particular attention is recommended to the existence of the intermediate neurocytic cells which may be unique for these tumors. Future implication with full molecular analysis for gene expression profiling is suggested for proper and accurate identifying this entity.

Ultrastructural Heterogeneity of Gangliogliomas

Gangliogliomas are rare brain tumors, composed of neuronal and glial cells mixed in a different proportion. The basic histopathological pattern of gangliogliomas is well recognized but the variable microscopic appearance still can pose a challenge to the neuropathologist. The authors reanalyzed their series of gangliogliomas in the files of two departments of neuropathology. All analyzed tumors fulfilled the WHO histological criteria of ganglioglioma. Seven tumors were examined by electron microscopy. The following ultrastructural features were graded: presence of dense-cored vesicles, synaptic vesicles, synapses and intermediate filaments, abundant basal membranes, dystrophic neurites, autophagic vacuoles, and multivesicular bodies. Most of the neoplastic neurons were large, polyglonal or oval with well-developed subcellular organelles, round nuclei, and prominent nucleoli. In most cases there were abundant dense core vesicles, observed in both the tumor cell bodies as well as in their processes. Synapses were typically observed. Intermediate filaments were abundant in all tumors. The most intriguing ultrastructural finding was abundant presence of autophagic vacuoles. In 4 cases, multivesicular bodies were observed. All of the tumors with multivesicular bodies also contained abundant autophagic vacuoles.

Extraventricular neurocytoma in a child: case report and review of the literature

Neurocytomas are relatively rare central nervous system tumors first described in intraventricular sites but increasingly recognized in the brain and spinal cord parenchyma. Herewith, we report a case of a 3-year-old girl with generalized seizures. Computed tomography and magnetic resonance imaging revealed a lesion in the left frontal lobe. Angiography showed minimal vascularity. The tumor was totally excised. Histopathologic examination demonstrated an extraventricular neurocytoma. On follow-up magnetic resonance imaging after 1 year, no evidence of tumor recurrence was noted. Cerebral neurocytomas are histologically low-grade tumors and radical surgery is curative; they should be included in the differential diagnosis of cerebral tumors in children.

Papillary glioneuronal tumor

Tumors of mixed glioneuronal type are well recognized in the central nervous system. The most common examples of these lesions include gangliogliomas and dysembryoplastic neuroepithelial tumors. Recently, unusual examples of these lesions have been described, including the papillary glioneuronal tumor. This report describes a histologically similar-appearing lesion arising in the left parieto-occipital lobe of an 18-year-old man who presented with headaches and difficulties with vision. Imaging studies noted a large cystic neoplasm marked by a peripheral rim of enhancement. The patient underwent gross total resection of the tumor, which histologically was marked by a mixture of glial (glial fibrillary acidic protein-positive) and neural (synaptophysin-positive) components. Architecturally, the tumor was notable for a focal pseudopapillary pattern. Papillae were lined by predominantly glial cells, with intervening areas occupied by neurally differentiated cells. Mitotic activity, vascular proliferation, and necrosis were not noted. A MIB-1 labeling index of 1.1% was seen. p53 immunoreactivity was not observed. This report adds further evidence supporting the existence of this unusual mixed glioneuronal tumor of the central nervous system.

Surgical pathology of intramedullary spinal cord neoplasms

The surgical pathology of intramedullary spinal cord neoplasms is most accurately based on radical resection specimens rather than on small biopsies, which may be highly misleading. A review of the neuropathology files at NYU Medical Center revealed 294 surgical specimens of intramedullary cord lesions examined between January 1, 1991 and December 31, 1998. Of these 117 were from children (age less than 21 years) and 177 were from adults (21 and over). While most types of central nervous system tumors known to occur in the brain also occur in the spinal cord, the different proportions of these tumors by histologic type, and the differences in the proportions of tumor types in children compared to adults, are both significant. In adults ependymomas are the predominant tumor type (93 total) while in children astrocytomas and mixed neuronal-glial tumors are virtually equally common and outnumber ependymomas. In this period no cord Primitive Neuroectodermal Tumors were identified. Among the astrocytic neoplasms and other gliomas, high grade tumors were distinctly uncommon in children and only slightly more common in adults, in sharp contrast with the brain, where the majority of adult intra-axial tumors are high grade.

Ganglioglioneurocytoma of the posterior fossa

OBJECTIVE AND IMPORTANCE

Ganglioglioneurocytoma is not yet a well defined clinical and histopathological entity; recent reports outline the histopathological features of this very rare trimorphous tumor, under different names with its basic components of gangliocytoma, neurocytoma and glioma. Four previous reports described this tumor in eleven patients. This is the first case report describing ganglioglioneurocytoma in the posterior fossa.

CLINICAL PRESENTATION AND INTERVENTION

A 31-year old male with midline posterior fossa ganglioglioneurocytoma is described, providing the neuroimages and histopathological studies.

CONCLUSION

Ganglioglioneurocytoma is a rare mixed neuronal and glial tumor that can also occur in the posterior fossa.

A distinctive glioneuronal tumor of the adult cerebrum with neuropil-like (including "rosetted") islands: report of 4 cases

Four examples of a novel glioneuronal neoplasm are presented. All tumors affected adults (including two males and two females aged 25-40 years) as supratentorial, cerebral hemispheric masses with associated seizure activity and, in one case, symptoms of raised intracranial pressure and progressive hemiparesis. CT scans in two cases revealed hypodense masses without calcification. MRI scans at presentation demonstrated, in all cases, solid T1-hypointense and T2-hyperintense tumors with mass effect in one instance but no edema or contrast enhancement. Only one was relatively circumscribed on neuroradiologic study. All were infiltrative in their histologic growth pattern and predominantly glial in appearance, being composed mainly of fibrillary, gemistocytic, or protoplasmic astroglial elements of WHO grade II to III. Their distinguishing feature was their content of sharply delimited, neuropil-like islands of intense synaptophysin reactivity inhabited and rimmed in rosetted fashion by cells demonstrating strong nuclear immunolabeling for the neuronal antigens NeuN and Hu. These cells included small, oligodendrocyte-like ("neurocytic") elements as well as larger, more pleomorphic forms. Two cases contained, in addition, well-differentiated neurons of medium to ganglion-cell size. Proliferative activity was observed principally within the glial compartment; two cases contained mitotic figures and exhibited relatively elevated MIB-1 indices (6.8% and 8.2%). One of the latter progressed and proved fatal at 30 months following subtotal resection and radiotherapy. The three other patients are alive at intervals of 14 to 83 months, two tumor-free and one with extensive disease associated with the appearance of enhancement on MRI. This glioneuronal tumor variant may pursue an unfavorable clinical course.

Lipomatous glioneurocytoma of the posterior fossa with divergent differentiation: case report

OBJECTIVE AND IMPORTANCE

We report a case of a posterior fossa neuroepithelial tumor with unusual clinical presentation, magnetic resonance imaging appearance, and morphological features.

CLINICAL PRESENTATION

This 66-year-old man presented with a history of gait ataxia, dizziness, and tinnitus and was found to have a large tumor in the posterior fossa and cerebellopontine angle.

INTERVENTION

Gross total excision of the tumor was accomplished. Histologically, the most unique features were macrovesicular accumulations of lipid, giving the tumor (at least focally) an appearance virtually identical to that of mature adipose tissue. Evidence of biphasic neuronal and glial differentiation was noted by immunohistochemistry and electron microscopy.

CONCLUSION

A literature review is presented. Diagnostically, this neoplasm seems to fit in a unique group of rarely described, lipomatous neuroectodermal tumors that show divergent neuronal and glial differentiation.

Clear cell ependymoma: a mimic of oligodendroglioma: clinicopathologic and ultrastructural considerations

Although clear cells resembling oligodendrocytes are known to occur in ependymomas, tumors composed primarily of such cells, i.e., clear cell ependymoma (CCE), are rare. Herein we characterize the clinicopathologic features of eight examples of CCE encountered at Mayo Clinic from 1983 to 1996. The tumors occurred in patients 3-31 years of age and presented as well-demarcated, deeply situated, contrast-enhancing masses, all of which were supratentorial. All but one case lacked classic light microscopic features of ependymoma. Although nearly all were immunoreactive for glial fibrillary acidic protein, it was electron microscopy that showed the diagnostic hallmarks of ependymoma, including complex intercellular junctions, surface microvilli and cilia, and microrosette formation, thus underscoring the importance of electron microscopy in the diagnosis of clear cell ependymomas. The differential diagnosis of CCE includes not only oligodendroglioma, but central neurocytoma and glioneurocytoma. Unlike oligodendrogliomas, CCEs are characterized by their sharp circumscription, hypervascularity as reflected in contrast enhancement on computed tomography and magnetic resonance imaging, their noninfiltrative pattern of growth that displaces parenchyma, and the occasional formation of vague perivascular pseudorosettes. Unlike central neurocytomas and glioneurocytomas, CCE lack secretory granules, vesicles, and synapses by electron microscopy and neuroendocrine markers by immunocytochemistry. In summary, the diagnosis of CCE requires neuroimaging, histologic, and ultrastructural correlation. The latter is essential in a limited biopsy. Ultrastructural studies also play a role in identifying glioneurocytomas. CCEs behave like more ordinary ependymomas. The importance of their recognition is the avoidance of alternative diagnoses and inappropriate therapies.

Extraventricular neoplasms with neurocytoma features. A clinicopathological study of 11 cases

The clinicopathological features of a series of neuronal and mixed neuronal and astrocytic neoplasms of the CNS are described. Patients were aged 5 to 63 years. Six cases were composed predominantly of small round cells with clear cytoplasm resembling central neurocytoma but lacked the characteristic intraventricular location of that tumor. The remaining five cases had similar neurocytomatous features associated with a benign astrocytic component. Ganglion cells and hyalinization vessels were observed in both groups. The growth fraction evaluated with monoclonal antibody Ki67Mib1 was low, ranging from 1 to 1.5%. Immunohistochemical detection of synaptophysin played a crucial role in identifying the neuronal nature of these neoplasms and was instrumental in distinguishing them from oligodendrogliomas, with which they are readily confused. The neuronal nature of the oligodendroglial-like cells was confirmed ultrastructurally in one case. The present cases, together with others reported previously, suggest that neoplasms of the CNS with "neurocytic" components are more frequent than generally assumed and expand the morphologic spectrum of neuronal and mixed neuronal-glial tumors. Except for one patient who died postoperatively, all patients were alive at follow-up ranging from 6 to 80 months.

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.