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[Malignant mediastinal lymph node tumors with unknown primary cancers].

PURPOSE
Malignant mediastinal lymph nodes with unknown primary tumor is a rare occurrence. The purpose of this study is to specify some characteristics of the patients presenting with this disease and to define an adequate therapeutic approach.


MATERIAL AND METHODS
Between 1985 and 1997, we have operated on 54 patients with isolated non-small cell malignancy to mediastinal lymph nodes. Forty-nine patients underwent surgical biopsy of the mediastinal mass, generally followed by radiation therapy and/or chemotherapy. A mediastinal lymph node resection was performed in 5 patients.


RESULTS
Five patients were lost to follow-up (9.3%). The 5-year survival rate and the median survival were 12.4 +/- 5% and 7 months respectively. Four of the 7 patients who were still alive after follow-ups ranging from 10 to 68 months had undergone a lymph node resection. During the follow-up, a primary tumor was discovered in only 5 patients (11.4%).


CONCLUSIONS
Patients with isolated malignant lymph nodes of the mediastinum have a poor prognosis. In order to improve their survival, we recommend a more aggressive therapeutic approach comprising a chemotherapy and a mediastinal lymph node resection, associated in some cases with a lung resection. Radiation therapy of the mediastinum can be administered, principally in case of incomplete resection.