The concurrence of granulomatous inflammation in intrathoracic lymph nodes with regional metastasis from primary lung cancer in surgically resected specimens

Introduction: Granulomatous inflammation has been associated with malignancies such as breast, testicular, renal cell, and lymphoma. The coexistence of granulomatous inflammation in mediastinal/hilar lymph node with primary lung malignancy has been described in case reports. Our goal was to examine the frequency of granulomatous reaction in mediastinal/hilar lymph node in the patients who had undergone surgical resection of lung cancer. Material and methods: We performed a retrospective analysis of 40 patients (1) aged ≥ 18 years and (2) who underwent lobectomy or pneumonectomy from August 1, 2012 to October 31, 2016 at Saint Louis University Hospital and (3) had pathology suggestive of cancer. Results: Of those 40 patients, 3 (7.5%) had granulomatous inflammation in the lymph nodes. None of these 3 individuals had evidence of metastasis in the particular lymph nodes with granulomatous inflammation. Conclusion: Our small cohort revealed that the presence of granulomatous inflammation in a lymph node can be safely taken as an evidence of the absence of metastasis to the lymph node. This finding can obviate the need for further sampling for the particular lymph node with granulomatous inflammation and can decrease the sampling time.