Suture foreign body granuloma masquerading as renal neoplasm.

Foreign body granulomas and pseudotumors due to retained surgical linen are well known in surgical practice. These lesions usually correspond to the actual size of residual foreign body and have characteristic presentation according to the anatomy involved. Renal suture granuloma is a rare postoperative complication of renal surgery due to persistence of sutures used to close the pelvicalyceal system/nephrotomy incisions and usually present as incidentally detected small mass lesions. This case of a suture foreign body granuloma presenting with hematuria, large peripheral mass lesion and characteristic computed tomography picture of renal cell carcinoma confounded the diagnosis and underwent laparoscopic radical nephrectomy. In retrospect, such lesions warrant the use of selective needle biopsy and intraoperative frozen section confirmation to clinch diagnosis. Mass lesions occurring in a previously operated kidney should have granuloma as a differential diagnosis.