Tumefactive fibroinflammatory lesion: A rare cause of chest pain

Tumefactive fibroinflammatory lesion (TFIL) is a rare idiopathic disease. These lesions clinically mimic malignant neoplasms, but they are characterized by benign histology while they cause local destruction. Its etiology is unknown, but it is thought to be an exaggerated immune response resulting from chronic infections. They are commonly seen in the head and neck area. Similar clinical and histologic findings are also present in IgG4-related disease. Here, it was aimed to present a 75-year-old male patient with chronic diseases including coronary artery disease and obesity. He was admitted to the thoracic surgery outpatient clinic with symptoms of chest pain, dyspnea, and swelling in the anterior chest wall. Imaging methods revealed a mass, which affected bone structures and showed increased 18-fluorodeoxyglucose (FDG) uptake, in the anterior of the left hemithorax. Surgical excision was performed because he met the clinical criteria of malignancy. No malignancy finding was identified in the histopathologic examination of the samples collected from the mass. In light of immunohistochemical and histopathologic findings, he was diagnosed as having TFIL. Treatment options for these lesions include steroids, surgery, and radiotherapy. They are persistent lesions associated with a high recurrence rate. We wanted to present this case because it is possible to recognize this rarely encountered lesion and increase awareness of the existence of such an entity.