Pulmonary staple granuloma mimicking lung cancer; report of a case

A 67-year-old man was referred to our hospital with chief complaints of bloody sputum and an abnormal chest shadow. He had a history of chronic renal failure and surgery for right pneumothorax. During dialysis treatment 2 years ago, an examination revealed a mass shadow with spiculation in the apex of the right lung. Subsequently, he noted bloody sputum, and the shadow became larger. Serum Progastrin-releasing-peptide (GRP) levels remained within the range of 70-80 pg/ml at the previous clinic, but were elevated to 109 pg/ml on admission to our hospital. These findings suggested lung cancer developing around the scar due to pneumothorax surgery, and we performed an operation. The resected tumor was a granuloma formed around a staple with a polytetra-fluoroethylene (PTFE) sheet, showing no evidence of malignancy. The patient's postoperative course was uneventful, and the serum Pro-GRP level fell to 60 pg/ml.