This book provides a comprehensive overview of the complex management of the oral tongue cavity. Oral tongue squamous cell carcinoma (OTSCC) is the most common cancer occurring in the oral cavity and is characterized by its aggressive malignancy and poorer prognosis compared to SCC in other oral locations. Radical surgery remains the primary treatment for OTSCC: the gold standard treatment for stages I-II OTSCC is transoral surgical excision. Conversely, stages III-IV OTSCC, with a DOI ≥ 10 mm, typically require 'en-bloc' tumor removal. The principles of Compartmental Tongue Surgery (CTS), proposed by L. Calabrese et al. in 2011, are based on the concept of an "anatomy-based oncologic compartment," encompassing the primary tumor and its potential muscular, vascular, nervous, and lymphatic pathways of neoplastic spread. In CTS, the extrinsic tongue muscles, even partially infiltrated by the neoplasm, are meticulously dissected from their bony insertions. The notion of 'en-bloc' removal extends to all anatomical structures and stromal tissue at risk for tumor localization, connecting the primary tumor to the cervical lymph nodes, identified as the "T-N tract". Due to its structured anatomy and the limited surgical field, achieving significant surgical radicality in oral cavity cancer is often challenging. This unique book aims to elucidate the concept of the oncological compartment and systematically reviews the oncological outcomes and advantages of the authors' approach to OTSCC. Additionally, it illustrates in detail practical, step-by-step guidance, from basic transoral to more complex compartmental emiglossectomy techniques for the management of tongue cancer. The authors share their knowledge and experience and provide common pearls and pitfalls in this specialized field.