Coal Worker’s Pneumoconiosis and a Sarcoid-Like Reaction Mimicking Lymph Node Metastases in a Patient With Lung Cancer: A Case Report

Sarcoid-like reactions occur in a small percentage of cancer patients. This reaction causes lymph nodes to appear hypermetabolic when viewed with Fludeoxyglucose-Positron Emission Tomography (FDG-PET). This is clinically important, because it could be confused with tumor metastasis and could affect the staging and treatment of the cancer. In addition to sarcoid-like reactions and metastasis, several other disease processes can cause lymph nodes to appear hypermetabolic with FDG-PET, including coal worker’s pneumoconiosis. We present the case of a 61-year-old coal miner who was diagnosed with lung cancer. FDG-PET showed increased uptake in ipsilateral and contralateral mediastinal lymph. The patient had bronchoscopy with endobronchial ultrasound (EBUS) guided biopsy of the mass and needle aspiration of bilateral lymph nodes of the mediastinum. All the biopsies were negative. The patient then had a left upper lobectomy and left mediastinal lymph node dissection. The PET findings were originally attributed to metastasis of the tumor, but pathology of the ipsilateral nodes showed silicotic changes due to pneumoconiosis and non-caseating granulomas from a sarcoid-like reaction. Because the ipsilateral lymph nodes had no evidence of metastasis and EBUS biopsy of the contralateral nodes was negative, 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 after surgery, the patient remains stable with no evidence of recurrence, and we have clinical assurance that the changes in the lymph nodes were due to the sarcoid-like reaction and pneumoconiosis and not metastasis. FDG-PET is useful for detection of lung cancer, but pathology is necessary for staging and determining treatment for the patient.