Kissing pleural metastases from metastatic osteosarcoma of the lung

Two patients with osteosarcoma lung metastases of which migrated to the parietal pleura due to contact are reported. The first patient was a 16-year-old male who had a pleural metastasis in the diaphragm within an area in contact with a single lung metastasis. Both of the tumors were resected, followed by systemic chemotherapy. Nine months after the resection of the first metastases, two other lung metastases were found which were resected after chemotherapy. The patient is alive without recurrence 84 months after the first resection of the metastases. The second patient was an 11-year-old female with a pleural metastasis of osteosarcoma which was within an area in contact with a single lung metastasis, which had been resected 4 months before. We concluded (1) that a lung metastasis of osteosarcoma occasionally metastasizes to the pleura due to contact; and (2) that because this kissing metastases of osteosarcoma could be cured by a complete resection, the intrathoracic cavity should be thoroughly observed.