Evaluating the superior vena cava syndrome.

We reviewed the records of 28 patients with superior vena cava syndrome (SVCS) between 1973 and 1978 to establish the risk from invasive diagnostic procedures and the therapeutic value of the information obtained. Of 23 patients, this syndrome was the initial manifestation in 18. Bronchoscopy with endobronchial biopsy, thoracentesis, pleural biopsy, lymph node biopsy, and, in one patient, thoracotomy were performed without major complications. Small cell undifferentiated carcinoma of the lung was found in seven of the 18 patients with SVCS as the initial manifestation of their disease. We believe that carefully performed invasive diagnostic procedures can be carried out safely. Furthermore, accurate histological diagnosis assumes major importance with the development of effective chemotherapy for small cell undifferentiated carcinoma of the lung.