Therapie von Thymomen und Thymuskarzinomen

[Mediastinal tumors : Diagnosis and treatment of the most common tumor entities]

The mediastinum is defined as the space formed ventrally by the sternum, dorsally by the spine, and laterally by the mediastinal pleura. A mediastinal mass is frequently an incidental finding. The wide spectrum of underlying diseases and the anatomic proximity to central structures makes diagnosis and treatment challenging. In many cases, the combination of anamnesis, physical examination, imaging and laboratory tests already provides valuable information about the tumor entity. In addition to diagnostic procedures for histological examination of an unclear mediastinal tumor, radical resection is very important for the prognosis of the patients, especially in the case of tumors of the thymus. Multimodal treatment of advanced tumors that involve adjacent structures is best performed in designated centers.

[Extended Resection of Locally Advanced Thymic Tumours in Stage III]

In the treatment of locally advanced thymic tumours, specific diagnostic testing is required, with a multimodal therapeutic approach consisting of surgery, radio- and/or chemotherapy. The complete resection of the tumour represents the most important prognostic factor with regard to recurrence-free and long-term survival. Local invasive growth of malignant thymic tumours into neighbouring mediastinal structures is classified as Masaoka-Koga stage III. Surgical resection can be performed primarily or after induction therapy, depending on the extent of the tumour. However, in some cases these tumours must be classified as non-resectable, so that only palliative radio-/chemotherapy remains as therapeutic option. TNM classification for malignant thymic tumours has been recently introduced. This resembles the established Masaoka-Koga classification in many aspects, but also includes some therapy-relevant changes. A differentiation is made between stages IIIA and IIIB, with the aim of assessing the resectability of advanced thymic tumours in a more differentiated manner and consequent planning of the therapy concept. Besides the thymus, thymoma, perithymic tissue, mediastinal pleura (stage I) or pericardium (stage II), all infiltrated structures should be removed "en bloc", if possible in stage III tumours. While the lung, brachiocephalic vessels or extrapericardial pulmonary vessels can still be resected and reconstructed if necessary, infiltration of the aorta or intrapericardial pulmonary vessels often limits macroscopically complete resection.