Mediastinal transthoracic needle and core lymph node biopsy - Should it replace mediastinoscopy?

Study objectives: Primary assessment of mediastinal lymph nodes (N2 or N3) for staging lung cancer by transthoracic needle with or without core biopsy. Mediastinoscopy only performed after FNA, failed to yield a diagnosis. Design and settings: A retrospective study in a university setting. Patients: Eighty-nine patients with mediastinal lymphadenopathy (> 1.5 cm in short-axis diameter) by CT. Methods: Mediastinal transthoracic fine-needle aspiration (FNA) with or without core biopsy was performed prior to mediastinoscopy in 89 patients with mediastinal lymphadenopathy (lymph node > 1.5 cm in short-axis diameter) or masses by CT. Results: Mediastinal transthoracic FNA was used alone in 39 of 89 patients, or with core biopsy in 50 of 89 patients. Mediastinal transthoracic FNA with or without core biopsy was diagnostic in 69 of 89 patients (77.5%) for cancer cell type, sarcoidosis, or caseating granulomas with or without tuberculosis. Transtboracic FNA with or without core biopsy of nodal stations (total, 94 biopsies) judged readily accessible by mediastinoscopy (n = 59) included paratracheal (n = 56) and highest mediastinal (n = 3); those more difficult (n = 26) included subcarinal (n = 20) and aorticopulmonary window (n = 6); and those impossible (n = 9) included paraesophageal and pulmonary ligament (n = 6), parasternal (n = 2), and para-aortic (n = 1). Innovative lung protective techniques for CT-guided biopsy access windows included "iatrogenic-controlled pneumothorax" (n = 10) or saline solution injection creating a "salinoma" (n = 11). Pneumothorax was detected in only 10% with a "protective" technique but 60% when traversing lung parenchyma. Transthoracic FNA with or without core biopsy failed to yield a diagnosis in 20 of 89 patients (22.5%); all then underwent mediastinoseopy', with 11 of 20 procedures (55%) diagnostic for cancer, and 9 of 20 procedures diagnostic of benign diagnosis or no cancer. Conclusion: Transthoracic FNA with or without core biopsy accesses virtually all mediastinal nodal stations is diagnostic in 78% of cases with mediastinal adenopathy or masses, and should precede mediastinoscopy in the staging of lung cancer or workup of mediastinal masses.