Molecular characterization of central neurocytomas: potential markers for tumor typing and progression.

Central neurocytomas (CNs) are rare intraventricular tumors presenting a favorable prognosis after surgery. Their transcriptomic profile is poorly characterized. We performed a microarray transcriptomic study to search for molecular markers that might improve diagnostic accuracy.

Histopathologic and ultrastructural features and claudin expression in papillary tumors of the pineal region: a multicenter analysis.

Neuroepithelial papillary tumor of the pineal region (PTPR) has been defined as a distinct entity that is increasingly being recognized, with 96 cases now reported. This tumor shares morphologic features with both ependymomas and choroid plexus tumors. PTPR is characterized by an epithelial-like growth pattern in which the vessels are covered by layers of tumor cells forming perivascular pseudorosettes.

Molecular characterization of circumventricular organs and third ventricle ependyma in the rat: potential markers for periventricular tumors.

Circumventricular organs (CVOs) are specialized ventricular structures around the third and fourth ventricles of the brain. In humans, these structures are present during the fetal period and some become vestigial after birth. Some of these organs, such as the pineal gland (PG), subcommissural organ (SCO), and organum vasculosum of the lamina terminalis, might be the sites of origin of periventricular tumors, notably pineal parenchymal tumors, papillary tumor of the pineal region and chordoid glioma.

Folate depletion changes gene expression of fatty acid metabolism, DNA synthesis, and circadian cycle in male mice.

Folate is essential for purine and thymidylate biosynthesis and in methyl transfer for DNA methylation. Folate deficiency alters the secretion of melatonin, a hormone involved in circadian rhythm entrainment, and causes hyperhomocysteinemia because of disruption of homocysteine metabolism. Adverse effects of homocysteine include the generation of free radicals, activation of proliferation or apoptosis, and alteration of gene expression.

Pleomorphic pineocytoma associated with normal pineal parenchyma: report of a case in a 70-year-old man.

Pineocytomas (PCs) most frequently occur in adults, but only three cases have been reported in women older than 70 years. In PCs, cytologic pleomorphism, accompanied by ganglion cells intensely expressing neuronal markers, has been described and the presence of pleomorphic cells may lead to an erroneous upgrading of the tumor. We report an unusual case of pleomorphic pineocytoma in an older patient who presented with a slowly growing tumor adjacent to residual pineal gland.

Histopathology of tumors of the pineal region.

Pineal region tumors are heterogeneous lesions and include mainly pineal parenchymal tumors (PPTs), papillary tumors of the pineal region (PTPRs) and germ cell tumors (GCTs). This article describes the cystic pineal gland compared with normal tissue and histopathological features of the most frequent pineal region tumors. PPTs are subdivided into pineocytoma (grade I), pineoblastoma (grade IV) and tumors with intermediate differentiation (PPTIDs; grades II-III).

P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) localize in the microvessels forming the blood-tumor barrier in ependymomas.

Ependymomas are neuroepithelial tumors that arise from the ependymal layer bordering the cerebral ventricles and spinal canal. Intracranial ependymoma represents a major encephalic tumor in children, while spinal ependymoma develops more frequently in adults. To understand the pharmacoresistance that characterizes this tumoral entity, we analyzed the level of expression and localization of three major efflux transport proteins with a multidrug resistance function, P-glycoprotein, multidrug resistance-related protein 1 (MRP1) and breast cancer resistance protein (BCRP), in a series of 25 ependymomas from both children and adults.

Microarray gene expression profiling in meningiomas: differential expression according to grade or histopathological subtype.

Meningiomas, one of the largest subgroup of intracranial tumours are generally benign, but can progress to malignancy. They are classified into the three World Health Organization grades: benign, atypical and anaplastic meningiomas. Various histopathological features have been associated with aggressiveness or recurrence.

Contribution of the daily melatonin profile to diagnosis of tumors of the pineal region.

Tumors of the pineal region (TPR) include different entities: germ cell tumors (GCT), pineal parenchymal tumors (PPT), meningiomas, and glial tumors. Except for GCT, there are no peripheral markers and histopathological diagnosis needs biopsy or surgery. We studied daily melatonin variations in twenty-nine patients with TPR and five with tectal plate glioma (TPG), used as controls, before and/or after surgery.

Bcl-2 expression in a papillary tumor of the pineal region.

Neuroepithelial papillary tumor of the pineal region (PTPR) has been described by several groups and recognized by the 2007 World Health Organization Classification of Tumors of the Central Nervous System. The proto-oncogen Blc-2 can function as an apoptosis suppressor and can promote neoplastic transformation. It may also be involved in neuroendocrine differentiation in some tumors.

Pineocytoma and pineal parenchymal tumors of intermediate differentiation presenting cytologic pleomorphism: a multicenter study.

Cytologic pleomorphism has been described in a limited number of benign pineal tumors, namely pineocytoma (PC) and pineal parenchymal tumors (PPTs) of intermediate differentiation (PPTID). We examined the clinicopathologic features in a retrospective series of 14 cases (seven females and seven males aged from 10 to 65 years) of pleomorphic PPT. Seven cases were PC, with no mitoses and with areas of tumoral cells forming large pineocytomatous rosettes and other areas with giant cells containing hyperchromatic nuclei.

Prognosis and histopathologic features in papillary tumors of the pineal region: a retrospective multicenter study of 31 cases.

Papillary tumor of the pineal region (PTPR) is a recently described tumor entity thought to arise from the specialized ependyma of the subcommissural organ. Whereas histologic features of PTPR are well defined, data on the prognostic value of PTPR remain scarce. We therefore investigated clinicopathologic features, including data on progression-free survival and overall survival, in a retrospective series of 31 PTPR.

Microarray analysis reveals differential gene expression patterns in tumors of the pineal region.

Several types of tumors are known to originate from the pineal region, among them pineal parenchymal tumors (PPTs) and papillary tumors of the pineal region (PTPRs), probably derived from the subcommissural organ. As a result of their rarity, their histologic diagnosis remains difficult. To identify molecular markers, using CodeLink oligonucleotide arrays, gene expression was studied in 3 PPTs (2 pineocytomas and one pineoblastoma), 2 PTPRs, and one chordoid glioma, another rare tumor of the third ventricle.

Fourth ventricle neurocytoma with lipomatous and ependymal differentiation.

We report the case of a 4-year-old girl with a fourth ventricle tumor diagnosed as a cerebellar liponeurocytoma which recurred, showing ependymal differentiation, 14 months after surgery. Magnetic resonance imaging at initial presentation revealed a large mass in the fourth ventricle, and histology showed a neoplasm characterized by a combination of well-differentiated neurocytes and cells resembling adipocytes. The tumor recurrence was histologically identical to the original tumor in some regions, but with fewer adipose-like cells, while other areas presented an endocrine architecture with oligo-like or pleiomorphic cells, and rosette-like arrangements of tumoral cells were seen around the thin vessels, with features similar to cellular ependymoma.

Identification of differentially expressed genes in human pineal parenchymal tumors by microarray analysis.

Human pineal parenchymal tumors (PPTs) are rare tumors, and little is known about their molecular pathogenesis. We used Atlas plastic human 8 K microarray analysis to identify the genes expressed in four human PPTs of different grades, in normal brain tissue and in a normal fetal pineal gland. We selected the most highly expressed genes in PPT (n=39) and compared their expression to that both in normal brain and fetal pineal gland.