[Thymoma--incidence, classification and therapy].

Thymomas are a rare tumor entity. However, they represent 50 % of all tumors of the anterior mediastinum. There are no specific early symptoms. Overall in 10 - 15 % of patients with myasthenia gravis a thymoma is evident. Two major classifications are relevant in clinical practise: the Masaoka-classification and the WHO-classification. For their clinical and prognostic significance both classifications should be used for patients with thymomas. Additional, only resection status (RO) is known as a significant prognostic factor. Thymomas are compulsory malignant tumors. Distant metastasis is found as well as local recurrence in all stages of the disease. The 5-year-mortality rate constitutes about 80 %, not meaning any healing because local recurrences occur as late as five years after surgery. 60 % of all patients die from tumor-independent reasons making a clear prognostic statement difficult. Surgical treatment remains the gold standard and must be performed whenever possible. The most common approach is a median sternotomy. When dealing with a thymuscarcinoma, radical lymph node dissection is advisable. With respect of treatment only adjuvant radiation can possibly improve long term survival and reduces local recurrence rates for incomplete resected patients. There is no evidence for a benefit in patients with thymoma receiving adjuvant chemotherapy. A neo-adjuvant chemotherapy in combination with an adjuvant radiotherapy improves outcome after surgical resection in stage III and IV and goes along with better survival rates. Larger studies have not been performed so far. A multimodal therapy strategy is advised when dealing with thymomas in stage III and IV.