[Mesothelioma of Unknown Primary Site with Resection of Mediastinal Lymph Node Metastasis].

A 63-year-old male underwent biopsy of a mediastinal lymph node. Intra-operative frozen section diagnosis was metastatic mesothelioma. The primary site of mesothelioma was not detected in the thoracic cavity. One year later, he was again removed a mediastinal lymph node metastasis, but the primary site was not detected. Eight months later, he was performed right neck and mediastinal lymph node dissection due to additionally appeared lymph node metastases, but the primary site was not detected. He is well 6 months after last surgery with postoperative adjuvant chemotherapy.