Staging of primary lung cancer by computed tomography-guided percutaneous needle cytology of mediastinal lymph nodes.

Background: The necessity of an easy and noninvasive technique to evaluate mediastinal node status cytopathologically is considered.
Methods: Eighteen cases of clinical N2 primary lung cancer were examined. Under local anesthesia, the lymph node was punctured with a 19-gauge needle using intermittent computed tomographic monitoring, and samples were studied cytologically. Subcarinal (no. 7) nodes and lower paratracheal (no. 4) nodes were sampled using the paraspinal posterior approach. Anterior mediastinal (no. 6) nodes were sampled using the parasternal anterior approach. Node status was diagnosed pathologically at operation.
Results: Number 7 nodes were examined in 11 cases, no. 4 nodes in 5 cases, and no. 6 nodes in 2 cases. Malignant cells were detected in 14 cases. Fourteen cases were diagnosed as true positive, 2 cases as true negative, and 2 cases as false negative. The sensitivity, specificity, and accuracy of this method were 88%, 100%, and 89%, respectively. Pneumothorax developed in 4 cases (22%).
Conclusions: Computed tomography-guided percutaneous needle cytology of mediastinal lymph nodes is useful for staging primary lung cancer. Because this is a small series, additional studies are necessary.