BackgroundAstroblastoma is a controversial and an extremely rare central nervous system neoplasm. Although its histogenesis has been clarified recently, controversies exist regarding its cellular origin and validity as a distinct entity. Because of its extreme rarity and because its common features are shared with other glial neoplasms, this tumor is prone to misdiagnosis and remains challenging not only in terms of diagnosis and classification but also in the subsequent management. This case report describes a new case of astroblastoma. It discusses clinical, radiologic, pathological, and therapeutic features and differential diagnosis of this rare neoplasm, with a review of the recent literature.Case presentationWe report the case of an 8-year-old Moroccan girl who presented with a 1-year history of epileptic seizure, headache, and decreased visual acuity. Cranial magnetic resonance imaging revealed a right occipito-temporal mass. A tumor resection was performed and histological examination combined with immunohistochemical study confirmed the diagnosis of low-grade astroblastoma.ConclusionsAstroblastoma is a very rare primary brain tumor. Its diagnosis is often challenging because of the astroblastic aspects that can be found in astrocytic tumors, in ependymomas, and in non-neuroepithelial tumors. Considerable confusion surrounds its histogenesis and classification. The low incidence rate makes it difficult to conduct studies to examine tumor characteristics.

Glioblastoma is the most aggressive malignant tumor of the central nervous system with a low survival rate. The difficulty of obtaining this tumor material represents a major limitation, making the real-time monitoring of tumor progression difficult, especially in the events of recurrence or resistance to treatment. The identification of characteristic biomarkers is indispensable for an accurate diagnosis, the rigorous follow-up of patients, and the development of new personalized treatments. Liquid biopsy, as a minimally invasive procedure, holds promise in this regard. The purpose of this paper is to summarize the current literature regarding the identification of molecular and circulating glioblastoma biomarkers and the importance of their integration as a valuable tool to improve patient care.

Glioblastomas are the most frequent and aggressive primary brain tumors which are expressing various evolutions, aggressiveness, and prognosis. Thus, the 2007 World Health Organization classification based solely on the histological criteria is no longer sufficient. It should be complemented by molecular analysis for a true histomolecular classification. The new 2016 WHO classification of tumors of the central nervous system uses molecular parameters in addition to histology to reclassify these tumors and reduce the interobserver variability. The aim of this study is to determine the prevalence of IDH mutations and EGFR amplifications in the population of the northeast region of Morocco and then to compare the results with other studies. Methods. IDH1 codon 132 and IDH2 codon 172 were directly sequenced and the amplification of exon 20 of EGFR gene was investigated by qPCR in 65 glioblastoma tumors diagnosed at the University Hospital of Fez between 2010 and 2014. Results. The R132H IDH1 mutation was observed in 8 of 65 tumor samples (12.31%). No mutation of IDH2 was detected. EGFR amplification was identified in 17 cases (26.15%). Conclusion. A systematic search of both histological and molecular markers should be requisite for a good diagnosis and a better management of glioblastomas.

Ewing sarcoma/primitive neuroectodermal tumor (Ewing/PNET sarcomas or EPS) are a group of round cell tumors. Malignant round cell tumors form a large and diverse group that includes rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, neuroblastoma, hepatoblastoma, Wilm's tumor, desmoplastic small round cell tumor, and other morphologically similar entities. Differential diagnosis of Ewing sarcoma/primitive neuroectodermal tumor (Ewing/PNET sarcomas or EPS) is difficult. In addition to morphology and immunohistochemistry (IHC), differential diagnosis of these tumors is based on molecular analysis of the EWSR1 gene rearrangement using fluorescent in situ hybridization (FISH) technique. We investigated the diagnostic value of combined CD99 immunostaining and EWSR1 t(22q12) alteration using a dual-color, break-apart rearrangement probe in forty-one formalin-fixed paraffin-embedded (FFPE) tissue samples from pediatric and adult patients diagnosed with EPS. IHC was performed in all cases using the CD99 antibody and showed a positivity of 92.7% in the enrolled cases (38/41) followed by FISH analysis where 48.8% of the cases (20/41) were rearranged. Sensitivity and specificity for IHC assays were 88% and 58%, respectively. Notably, FISH had a sensitivity of 100% and a specificity of 87%. In addition, CD99 positivity was found to correlate with EWSR1 rearrangement (p < 0.05). This report shows that FISH has better sensitivity and specificity than IHC in the Moroccan population, and supports its combination with CD99 immunostaining as diagnostic biomarkers for this rare malignant entity.”

Background Xeroderma pigmentosum (XP) is a rare autosomal recessive skin disorder characterized by hyperpigmentation, premature skin aging, ocular and cutaneous photosensitivity with increased risk of skin tumors. XP is caused by mutations in DNA repair genes that protect cells from UV-induced DNA damage. The current study aims to investigate, on clinical and genetic basis, Moroccan XP patients. We explored by direct sequencing the involvement of the prevalent XPA and XPC genes mutations: nonsense mutation (c.682C>T, p.Arg228X) and a two-base-pair (2 bp) deletion (c.1643 1644delTG or p.Val548Ala fsX25), respectively, in 40 index cases from 37 unrelated families in Moroccan population. Results Early skin and ocular manifestations were detected with high rate of malignancy. Cutaneous lesions progressed to malignant skin tumor in 70% of cases. Ocular tumors were also observed in 11 patients including BCC in eight cases, SCC in three cases and melanoma in four cases. Among the 40 patients, there were 20 homozygous cases for the 2 bp deletion in the XPC gene and 9 homozygous cases carrying the nonsense XPA mutation. Conclusion These findings obtained in the present study revealed that the XPC gene mutation (c.1643 1644delTG, p.Val548AlafsX25) is the major cause of Xeroderma pigmentosum in our population. The c.682C>T (p.Arg228X) mutation is relatively associated with moderate phenotype in XP group A Moroccan families. This result will also contribute to improving the molecular diagnosis of XP disease and will have a significant impact on improving the care of Moroccan patients and their relatives.