Classification, Pathology, Genetics, and Molecular Biology of Primary Tumors of the Osseous Spine

Primary tumors of the osseous spine represent a diverse group of entities with varying prognostic and therapeutic implications. This chapter provides an exhaustive review of their classification, pathology, genetics, and molecular biology, as per the latest World Health Organization (WHO) guidelines. It delineates the categorization of these neoplasms into benign, intermediate, and malignant classes, each with distinct biological behaviors and clinical outcomes. Radiological staging, a cornerstone of diagnostic accuracy, is discussed with an emphasis on the integration of computed tomography (CT), positron emission tomography (PET)/CT, and meticulous biopsy techniques. Such approaches are critical for the precise localization and characterization of spinal lesions, guiding therapeutic decision-making. Pathological assessment distinguishes between benign and malignant tumors, underscoring the prognostic and management nuances. Genetic profiling, including the identification of pathognomonic markers such as the EWSR1-FLI1 fusion in Ewing’s sarcoma, provides insights into tumor pathogenesis and potential avenues for targeted therapy. Molecular diagnostics emerge as a transformative tool, enabling the subclassification of histopathologically similar tumors, which is essential for individualized patient management. The chapter advocates for a multidisciplinary strategy, incorporating pathology, genetics, molecular biology, and imaging to optimize patient care. This chapter aims to provide clinicians and researchers with a thorough understanding of the complexities of spinal tumors, supporting the advancement of diagnostic and therapeutic modalities in spinal oncology.