PRIMARY retroperitoneal malignancies and malignant schwannomas are rare. Their occurrence together has been reported in only 14 patients. Stout1 reviewed 137 malignant tumors of peripheral nerves, and six of these tumors were located in the retroperitoneal area. Ackerman2 describes a retroperitoneal malignant schwannoma and mentions three others tabulated by Stout in a series from Columbia University. Carpenter and Kernohan3 found four cases of malignant schwannomas arising in the retroperitoneal area, in a study of the Mayo Clinic material over a 33-year period, which excluded cases of von Recklinghausen's disease.
Chylous effusions are generally associated with trauma or neoplasms. The neoplasms most frequently encountered causing chylous effusions are metastatic carcinomas, lymphomas, and rarely sarcomas, as indicated in the Table.4-7 Nix 7 reviewed 302 cases of chylous effusions, 84 of which were caused by neoplasms. Wallis and Scholberg4 enumerated 233 cases of chylous effusions of which 81 were due to malignancies, six