Incidence of SCLN Metastasis in Patients Referred for EBUS-TBNA

Evaluation of the anatomic extent of a primary lung cancer and presence of metastasis are essential for selection of an appropriate management strategy. Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a reliable and established technique to evaluate involvement of mediastinal lymph nodes (LN); however, it is an invasive procedure and may not be tolerated in patients with severe underlying lung disease. One exception is the superficially located supraclavicular lymph nodes (SCLN), which can easily be biopsied with percutaneous US-guided-fine needle aspiration (US-FNA). Traditionally, this nodal group is evaluated by palpation; however, literature suggests that palpation itself fails to capture 66% of proven disease by cytology, which challenges the acceptance that non-palpable nodes are indicative of absent disease. Since all palpable SCLN are biopsied to rule out metastasis, we may potentially up-stage more patients using ultrasound evaluation for non-palpable nodes; and offer more appropriate management. Currently, the incidence for non-palpable SCLN metastasis has not been defined in this patient population presenting for EBUS-TBNA. The primary objective is to determine the incidence of supraclavicular lymph node metastasis by ultrasound evaluation in patients referred for EBUS-TBNA.