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Cancer is the second leading cause of morbidity and mortality worldwide, ranking just after cardiovascular diseases. In the central nervous system, gliomas constitute the most frequent type of tumors. According to the definition, oligodendrogliomas are diffusely infiltrating glial tumors, composed of neoplastic oligodendroglial cells, typically found in cerebral hemispheres in adult population, although not uncommon in children. They encompass a range of tumours, from well-differentiated to frankly malignant neoplasms. In the current World Health Organization (WHO) classification of tumors of the central nervous system, covering a four-tiered WHO grading scheme, oligodendrogliomas are recognised as grade WHO II and WHO III by the degree of malignancy. They may be either well differentiated, composed of neoplastic cells that morphologically resemble oligodendroglia, or may harbor focal or diffuse features of malignancy, respectively. Their prognosis is in this case less favorable. This book provides current research on the diagnosis, outcomes and prognosis of oligodendrogliomas. Chapter one examines the pathology, molecular mechanisms and clinical references of ODs. Chapter two discusses the ODs and the problematic diagnostic markers. Chapter three examines the histopathologic features of oligodendrogliomas and of an assortment of other central nervous system neoplasms that can resemble them and reviews features that allow one to sort through these histopathologic differential diagnoses. The final chapter reviews speech mapping in oligodendroglioma operations and provides data regarding patient outcomes with these methods.

Gliomas represent some of the most difficult tumors to understand and most challenging to treat. As illustrated in this book, the difficulty in understanding them is apparent in various ways. They have significant diversity in histology, genomic alternations, protein expression, clinical presentation, radiographic appearance, treatment approaches, and ideas of how to cure them. Our current understanding of the genetic mutations and signaling pathways that drive these tumors has greatly expanded our knowledge and at the same time, our uncertainty about how to combat these tumors. Added to this complexity is the fact that we are typically talking about tumors that infiltrate through an organ that many of us consider the “seat of our souls,” where we must exercise the utmost caution in how we deliver treatments with great risks. This book begins with an introduction to this complex topic with a broad overview of grading criteria, histological features, common genomic alterations and affected signaling pathways, and current treatments. Most exciting is an extensive discussion on new therapeutic concepts and delivering mechanisms that arise from the complex field of nanotechnology where nanoparticles, nanotubes, and nanocrystals may someday become the Trojan horse. Subsequent chapters are devoted to unique situations such as brainstem gliomas and gliomas in our pediatric population, where tumors and patients can behave very differently from their adult counterparts. Before devoting several chapters to the biology of these tumors, the book discusses surgical and radiotherapeutic aspects of the glioma field. One chapter focuses on a growing trend to minimize approaches to reduce morbidity, by the use of customized craniotomies, endoscopy and potential robotics in the near future. Another chapter is devoted to current common imaging characteristics with an excellent description of its limitations in describing the clear biological heterogeneity. Future imaging modalities will likely move toward more functional, metabolic, and protein-specific forms of imaging to diagnose, deliver treatments, and monitor response to treatments. The last decade has certainly witnessed significant gains in areas that will contribute to making progress in glioma treatment. In malignant gliomas, we finally have established a trimodal “standard of care” on which all glioma clinicians agree, all glioma patients hopefully receive, and with which we can compare future experimental trials. We have an encyclopedic knowledge of the molecular biology behind these tumors, and now need to figure out where to exploit it. Imaging and drug delivery methods are achieving impressive sophistication. The challenge of the next decade will be to bring focus to our strategies and to channel them through increasingly complex, costly and lengthy clinical trial designs.