Conventional techniques: Transthoracic approach

Thymomas are the most frequent neoplasms of the anterior mediastinal compartment, accounting for approximately 20% of all mediastinal tumors in adults. They are, however, a rare neoplasm, with an incidence of approximately 0.15 cases in 100,000 habitants per year in the USA [1]. Thymomas are neoplasms of epithelial origin which, despite being considered tumors with an often indolent growth pattern, have a well-documented capability to invade adjacent structures and develop metastases in the pleura as well as, though more rarely, distant metastases. Although several histological classifications have been proposed over the last few years, today there is a wide consensus on the use of the classification proposed by the World Health Organization (WHO) in 1999, as reviewed and confirmed in 2003, which breaks down thymic neoplasms into 6 groups based on the presence of cellular atypias and based on the relationship between epithelial and lymphatic cells (Table 16.1) [2]. By now, a unanimous consensus has been reached on the staging system proposed by Masaoka in 1981 and reviewed in 1994 (Table 16.2) [3], which classifies neoplasms based on the presence or absence of a macroscopic or microscopic invasion of the capsule, of adjacent structures, and the presence of metastases. © 2008 Springer Milan.