Granulomatous inflammation detected by endobronchial ultrasound-guided transbronchial needle aspiration in patients with a concurrent diagnosis of cancer: A clinical conundrum

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is increasingly used for evaluating mediastinal and/or hilar lymphadenopathy in patients with malignancy. Granulomatous inflammation is occasionally identified in this setting and has unclear clinical implications. Therefore, we set out to describe a cohort of patients found to have evidence of granulomatous inflammation during EBUS-TBNA done for diagnosis and/or staging of concurrent cancer. Methods: A retrospective analysis of all EBUS-TBNA cases performed over 32 months at our institution was completed. Patients with evidence of granulomatous inflammation during EBUS-TBNA that was not attributable to an infectious etiology or prior sarcoidosis and a concurrent diagnosis of cancer were included. Results: Granulomatous inflammation was identified in 154/1275 patients (12.1%), of whom 12/154 (7.8%) had a concurrent diagnosis of cancer. Primary cancer diagnoses varied, but the primary site of malignancy was in or near the thorax in 10/12 cases (83.3%). When available, 7/8 cases (87.5%) of granulomatous lymphadenopathy were detectable by positron emission tomography. The most common histologic pattern consisted of well-formed non-necrotizing granulomas without fibrosis in 6/12 patients (50%). Conclusions: Granulomatous inflammation is occasionally identified in mediastinal and/or hilar lymphadenopathy in patients with concurrent malignancy. Although the clinical implications of this phenomenon remain to be clarified, these findings emphasize the importance of histologic confirmation of suspected lymph node involvement and suggest that the presence of granulomatous inflammation on EBUS-TBNA may occasionally be consistent with active malignancy and prompt further investigations.