LAUSR

Malignant thymomas are rare invasive tumors which arise from the thymus gland. They represent the most common tumors of the anterior mediastinum. Neoadjuvant chemotherapy is indicated for locally advanced tumors. Complete responses are very rare. These tumors have a high risk of relapse. Most common sites of relapses are in the thoracic cavity and then in the mediastinum and lungs [1]. Central nervous system involvement is unusual in malignant thymomas. Although brain has been described as a site of infrequent metastases [2], only one case of synchronous leptomeningeal metastasis (LM) has been reported in the literature [3]. We here report a case of an advanced malignant thymoma which achieved an unexpected complete response with neoadjuvant chemotherapy. An exclusive meningeal relapse was diagnosed 11 months later.