"Bubble-like" lung metastases in osteosarcoma patients.

PURPOSE Cavitation of pulmonary metastases have been reported by several authors either as a spontaneous phenomenon or as a consequence of chemotherapy. We present two cases, with this type of image in follow-up, and 20-45 months after the end of treatment. This was the first sign of pulmonary metastases. RESULTS Two patients with osteogenic sarcoma developed radiological evidence of pulmonary "bubble-like" cavitation several years following completion of chemotherapy. In one patient the "bubble-like" cavitation transformed into a solid nodule. Both patients had surgical resections of all pulmonary lesions, and histology confirmed presence of viable osteosarcoma metastases. CONCLUSION The two cases suggest that onset of "bubble-like" cavitation in lung parenchyma of osteosarcoma patients may be the first sign of pulmonary metastases.