Endobronchial ultrasound (EBUS) transbronchial needle aspiration (TBNA) in germ cell cancer patients with mediastinal lymphadenopathy: A single centre retrospective analysis

Introduction: Germ cell cancer (GCC) is a solid tumour entity with excellent prognosis. However, thoracic manifestations such as mediastinal lymph node involvement or lung metastasis occur and affect prognosis. The occurrence of sarcoidosis/sarcoid like lesions (SLL) in GCC patients is frequently described. To differentiate between SLL and metastasis tissue sampling in GCC patients with pulmonary nodules or hilar and/or mediastinal lymphadenopathy is necessary. Methods: To analyze the frequency of SLL, we evaluated histological and/ or cytopathological results of n=621 patients, who were investigated by EBUS during 2009 to 2015 at Munster University Hospital. Focus was put on the coincidence of GCC and noncaseating granuloma . Results: In total n=621 EBUS procedures were evaluated. In n=6 patients (1%) GCC was the main diagnosis. Five patients belonged to the IGCCCG good prognosis sub-group and one patient belonged to the IGCCCG poor prognosis sub-group. SLL lesions where diagnosed in n=5 GCC patients (0.8%). Metastatic disease was diagnosed in none of the GCC cases investigated by EBUS. In the only GCC patient without SLL lymphadenitis with anthracosis was diagnosed instead. Conclusion: Our retrospective analysis demonstrated the coincidence of GCC and SLL to be a frequent finding. EBUS-TBNA is a safe diagnostic approach to confirm SLL. Therefore, aggressive diagnostic approaches such as mediastinoscopy can be avoided. Still, both the prognostic and the immunologic impact of SLL in GCC remain unclear. Further studies should investigate the underlying biological mechanisms and the impact on prognosis.