Patients undergoing EBUS with TransBronchial Needle Aspiration will be invited to enroll on the day of their procedure. Once informed consent is obtained, the surgeon will assess the sonographic criteria, take pictures, and biopsy every lymph node of interest. All three elements of this assessment will need to be completed for a specimen to be included in the study. After the procedure, the operating surgeon will fill the Lymph Node Assessment questionnaire, assign an aggregate score to every lymph node specimen, and attach the pictures to the form. Pictures from every specimen will stored electronically to be reviewed and secondarily rated by a second blinded surgeon. Patient involvement in the study ends at the completion of the planned procedure.

Objective is to compare the lymph node malignancy predictor score obtained by two raters, one who performed the procedure and the other a secondary rater who viewed the video of the procedure. The score will ideally be similar between raters, showing good inter-rater internal validity.

As the gold standard for lymph node assessment is via tissue sampling obtained during an EBUS (or other invasive method) procedure, the scores obtained using the lymph node malignancy predictor scoring technique will be compared to later post-surgical pathological staging. The score will be considered to have good criterion (external) validity if there is a high degree of agreement between the pathology and score values.

If the original tissue samples taken during the EBUS procedure were found to be insufficient to rule out malignancy, the patient may undergo another EBUS, or will undergo an Endoscopic ultrasound or a mediastinoscopy. During these follow-up procedures, the surgeon would be obtaining additional tissue in the hope that a result can be made. These re-intervention is not without a risk of adverse events, and ideally should be minimized. We will be abstracting re-intervention occurrences from patient charts.