Myasthenia gravis as a prognostic marker in patients with thymoma

Thymic epithelial tumors (TET) are mainly composed of thymomas (T) and thymic carcinomas; they are the most common primary neoplasms of the anterior mediastinum. Thymomas are the most frequent mediastinal neoplasm, their frequency is about 20% of cases (1,2). Thymic carcinomas are more aggressive neoplasms and their relation with autoimmune diseases is extremely rare, due to its cytological atypia and lack of thymus like features (2). Compared with all cancers, thymomas account for less than 0.5%, with an incidence of 0.15 per 100,000 person years (3). The mean age at the time of diagnosis is 52 years, without gender predominance. TET are usually asymptomatic and are found as an incidental mediastinal mass in chest X-ray. One-third of the patients with TET have chest pain, cough or dyspnea related to tumor compression or invasion (4)