Benefit of a second opinion: From metastatic disease to resectable lung cancer with sarcoid-like reaction

BACKGROUND Mediastinal lymphadenopathy in combination with lung cancer is suggestive for lymph node metastases but can also have other origins. CASE REPORT We describe a patient diagnosed with stage IV lung cancer presenting with parenchymal lesions and enlarged mediastinal lymph nodes. A second opinion including FDG-PET scan review and a mediastinoscopy followed by surgery revealed tumor specimens originating from a single primary tumor with a sarcoid-like reaction in the mediastinal lymph nodes, changing the diagnosis from metastasized to resectable lung cancer. DISCUSSION PET positive lesions are not always synonymous with metastatic disease in the presence of a malignant tumor. Conscientious review of FDG-PET scans and tissue sampling are therefore mandatory to determine definitive staging and subsequent interventions.