Lung and Mediastinal Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Young Adults

Introduction: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is used to investigate pulmonary nodules, mediastinal lymphadenopathy, and mediastinal masses in both malignant and nonmalignant etiologies. EBUS-TBNA is most commonly used in the diagnosis and staging of patients with non-small-cell lung cancer in the middle-age and elderly populations. As lung cancer is uncommon in young adults, it is assumed that there are a distinct disease population and clinical background in young adults who undergo EBUS-TBNA. However, this population has not been well investigated. Methods: We identified all EBUS-TBNA cases in young adults (aged 18-39 years) between January 1, 2008, and December 31, 2018, at our institution. Cytology diagnoses were correlated with the concurrent/subsequent histologic diagnosis and clinical decisions. A final patient classification was created based on the worst cytologic or histologic diagnosis (benign, low-grade, or malignant), with the exception of atypical cytology with subsequent long clinical follow-up with no evidence of malignancy, who were considered benign. All discordant cases and positive/suspicious cases with available slides were rereviewed together by the authors to confirm the diagnosis. Results: In total, 257 EBUS-TBNA procedures were performed in 249 young adults (mean age of 31.2 years). The majority of indications were lymphadenopathy and lung nodule/mass. Final cytologic interpretations included 214 (83%) benign, 14 (5%) atypical, 5 (2%) low-grade neoplasm (carcinoid tumor), and 15 (6%) malignant cases. The final patient classification was 213 (86%) benign, 6 (2%) low-grade, and 30 (12%) malignant. Discordant results were found in 24 cases, most frequently due to sampling error (50%). Of 213 benign cases, 58% had granulomatous disease, with sarcoidosis being the most common, followed by histoplasmosis. Of 30 cases with a final malignant classification, metastatic tumor was the most common (n = 12, 4.8%), followed by primary lung tumor (n = 11, 4.4%) and lymphoma (n = 7, 2.8%). There was a variety of malignancies among primary lung cancer, including adenocarcinoma (n = 5), squamous-cell carcinoma (n = 3), inflammatory myofibroblastic tumor (n = 2), and epithelioid hemangioendothelioma (n = 1). Conclusion: In young adults, EBUS-TBNA was most frequently performed to evaluate lymphadenopathy and lung nodules, and granulomatous disease was the most common benign finding. Although rare, primary lung malignancies do occur in young adults along with metastasis from a variety of other sites, with sarcoma being the most common pathology.