CASE PRESENTATION: We present the case of a 61 year old coal miner who was diagnosed with lung cancer. FDG-PET showed increased uptake in mediastinal lymph nodes on both the ipsilateral and contralateral side, however bronchoscopy and endobronchial ultrasound guided biopsy (EBUS) were negative. Because the mediastinal lymph node biopsy was negative, the patient was taken for surgical resection, and had a left upper lobectomy and left mediastinal lymph node dissection. The PET findings were originally thought to be due to metastasis from the tumor, however, pathology of the ipsilateral nodes showed the presence of silicotic changes due to CWP, and non-caseating granulomas, from a sarcoid like reaction. Because the ipsilateral lymph nodes had shown no evidence of metastasis, it was unlikely that the changes in the contralateral nodes were due to metastasis, and no adjuvant treatment was offered. At more than one year postoperatively the patient remains stable with no evidence of recurrence of the cancer, and we have clinical assurance that the changes in the lymph nodes were due to the sarcoid like reaction and CWP, and not metastasis.