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The primitive neuroectodermal tumours of central nervous system (CNS-PNET) are a heterogeneous group of neoplasms, occurring in the CNS and composed of undifferentiated or poorly differentiated neuroepithelial cells which may display divergent differentiation along neuronal, astrocytic and ependymal lines. The WHO classification includes in this group of tumours also ependymoblastomas and medulloepitheliomas. Several groups have reported examples of CNS-PNET with combined histological features of ependymoblastoma and neuroblastoma, defined as 'embryonal tumour with abundant neuropil and true rosettes'. The presence of the amplification of chromosome region 19q13.42, common in both ependymoblastoma and embryonal tumour with abundant neuropil and true rosettes, suggests that they represent a histological spectrum of a single biological entity.We examined 24 cases of ependymoblastoma/embryonal tumour with abundant neuropil and true rosettes (EPBL/ETANTR) for the presence of mutations of TP53 and β-Catenin and for amplification of c-myc/N-myc.The single strand conformation polymorphism-mutational screening did not identify any mutation in exons 5 to 8 of the TP53 gene. However, we found a point mutation affecting codon 34 (GGA → GTA) of β-Catenin gene resulting in a Glycine → Valine substitution. No cases presented c-myc/N-myc amplification.EPBL/ETANTRs show molecular features different from other CNS-PNET and medulloblastomas. The presence of alterations in the β-Catenin/WNT pathway seems to be noteworthy due to the close relationship between this pathway and miR-520g encoded in chromosome 19q13.42 region amplified in these tumours.

Purpose: Aggressive pituitary adenomas (APAs) and pituitarycarcinomas (PCs) are challenging for their invasive nature, resistance to treatment and recurrences. Temozolomide (TMZ) is used with benefit and well-tolerated toxicity profile in APAs and PCs. In most studies patients received ≤ 12 cycles but the best length of treatment is debated since other options after discontinuation are scarce and a second course is mainly unsuccessful. Methods: We report outcomes of 8 patients with APAs and PCs treated with TMZ for more than 12 continuous cycles with a literature review. Data were retrospectively collected from Padua and Milan University Hospitals. TMZ was used as a single agent (150–200 p.o. mg/m2 daily, 5/28days) for 14 to 45 cycles. Results: Eight patients (7M), 7 APAs and 1 PC. Previous treatments included neurosurgery and radiotherapy in all cases except two giant masses (ACTH-silent APA and prolactinoma). No patient had progression disease (PD) during long-term treatment nor toxicities. No one had complete response (CR) but four had partial response (PR). Four ACTH+ tumors maintained stable disease (SD) but the secretion pattern improved in all. After drug withdrawal, three had delayed PD (2 after 18 and one after 29months, all ACTH+); two are still in SD. Conclusions: TMZ may be useful and well-tolerated in APAs and PCs as a long-term therapy. PR appears within the first cycles with no escape throughout the treatment; most patients achieve SD. We suggest extended protocols particularly in responsive ACTH+ PAs and PCs, when further therapies may be unsuccessful.