Metastatic potential of metastases.

Nine cases of known metastases originating from other metastatic foci were documented at operation. The primary tumors included four melanomas, two osteosarcomas, a synovial sarcoma, an anaplastic lung carcinoma, and a rhadbomyosarcoma. Secondary metastatic sites to the regional lymph nodes were noted in the pulmonary hilum (one), mediastinum (one), pulmonary hilum and mediastinum (three), small bowel mesentary (two), retroperitoneum (one), and axilla (one). All patients were immunocompetent as evidenced by their ability to be sensitized to 2,4-dinitrochlorobenzene (DNCB) and/or their positive response to common skin test antigens. The metastatic potential of cells from metastases does not appear to differ from cells of the primary.