This document discusses procedures for lesions of the anterior mediastinum. It begins by describing the preoperative evaluation, which can help determine the tumor type based on clinical features and imaging. It then discusses the different tumor types that commonly occur in the anterior mediastinum, including thymomas, lymphomas, and germ cell tumors. The document provides guidance on whether to perform a biopsy or direct resection for different tumor types. It describes various surgical approaches for biopsying and resecting anterior mediastinal masses, such as the Chamberlain procedure, transcervical approach, median sternotomy, and others. The goal of surgery depends on the tumor but generally involves obtaining a diagnosis or achieving a complete resection with clear margins.