An amazing cause of false PET positivity: Diagnosed after a lung cancer surgery.

Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has an effective role in both diagnosis and management of patients with lung cancer. There are many reasons could cause false positivity on PET/CT.A 60-year-old man was admitted a mass on thorax CT and diagnosed as squamous cell carcinoma. Lobectomy with lymph node dissection was performed after evaluation of distant metastases. There were pathological lymph nodes detected on PET/CT at six month following period. Endobronchial ultrasonography guided transbronchial needle aspiration was performed for differantial diagnosis. The pathologic diagnosis was granuloma which developed in response to suture material. We interpreted this granulomatous reaction as gossypiboma which developed against long-left or forgotten suture material. In conclusion, based on this case, gossypiboma (or granulomatous inflammation in response to foreign bodies) should be also considered in differential diagnosis of intrathoracic lymph nodes with PET positivity in a previously operated patient.