Autoimmune diseases associated with thymoma

Thymoma is the most common neoplasm of the anterior mediastinum. This neoplasm is composed with neoplastic epithelial cells and non-neoplastic T lymphocytes with varying degrees. In the advanced stage of thymomas, recurrence is not uncommon, and treatment for recurrent lesions— especially disseminated lesions—is not easy. In addition, thymoma is often associated with autoimmune diseases. The representative disorder is myasthenia gravis (MG). Combined treatment for recurrence and complex autoimmune diseases is often difficult. The efficacy of thymectomy for early-onset MG without thymomas was demonstrated in a recent clinical trial, and it may be effective for MG patients associated with thymoma. However, thymectomy or thymomectomy usually does not affect other non-MG autoimmune diseases. Thymectomy has been performed via median sternotomy for many years, and thoracoscopic or mediastinoscopic thymectomy has been reported often. We established a subxiphoid approach to thoracoscopic thymectomy, and its usefulness and efficacy have been reported. In this section, the detailed procedures of thymectomy using this subxiphoid approach are introduced.