Dear Editor: Foreign body reaction is a tissue response to extraneous materials such as injected materials or implanted medical devices1. Here, we report a unique foreign body reaction caused by a retained cuff from a central venous catheter. A 63-year-old male patient with a history of end-stage renal disease presented with an asymptomatic, firm mass on the right chest for several months. One year ago, because of swelling and tenderness on the continuous ambulatory peritoneal dialysis (CAPD) catheter site, his CAPD catheter was removed, and a hemodialysis (HD) catheter was inserted through the right internal jugular vein. The CAPD catheter was reinserted after 2 weeks, and the HD catheter was removed by manual traction after 2 months. The patient visited our clinic with a 2 cm, skin-colored, subcutaneous mass on the right chest (Fig. 1). On incisional biopsy, there was an odorous, pus-like drainage and pieces of foreign material (Fig. 1). Histological examination showed groups of fibers with adjacent granulation tissue (Fig. 2). He was referred to the Department of General Surgery, and the catheter remains were completely removed. He had no complications. Fig. 1 (A) A solitary, 2 cm-sized, firm, skin-colored subcutaneous mass on the right chest. (B) Great chunks of pieces of foreign material (catheter cuff) identified during biopsy. Fig. 2 (A) Histopathology showing foreign body from the catheter cuff with adjacent granulation tissue (H&E, ×100). (B) Higher magnification view showing a granulomatous reaction with lymphocytes, histiocytes, multinucleated giant cells, and ... Venous access catheters are used for treatments such as HD and chemotherapy. Many catheters have polyester cuffs at the end for anchorage to the subcutaneous tissue. The catheters can be removed by traction or with a cutdown procedure2,3. When catheters are removed by traction, parts of the cuffs can break off and be retained in the subcutaneous tissue in 10%~50% of cases2. The reported complications of retained cuffs include infection, abscess, discharge, and delayed healing2,3. Our patient had an odorous, pus-like drainage; however, we did not perform bacterial culture or Gram stain. Antibiotics were given, and the wound site healed without complications. Retained cuffs are clinically insignificant unless infection occurs2,3,4. In a study by Kohli et al.3, 428 cuffed central venous catheters were removed by traction, and catheter cuffs were retained in only 41 (10%) of the patients. Of these 41 retained catheter cuffs, only 3 required removal. One was removed because the cuff migrated to the exit site, inhibiting healing. The other two were removed because of persistent erythema and swelling at the cuff site and for cosmetic purposes3,4. Currently, catheter manufacturers recommend removing all retained cuffs with a cutdown procedure2,3,4. However, while retained cuffs rarely cause problems, the cutdown procedure has risks of infection and scarring3,4. Therefore, as the risks associated with the cutdown procedure are greater than those of non-removal of the retained cuffs, Kohli et al.3 recommend leaving behind the retained cuffs3,4. In our case, owing to the patient's request, the retained cuff resulting from traction removal was completely removed by using a cutdown procedure, and there were no complications. In the Korean literature, there have been many cases of foreign body reactions due to materials such as fillers, and bee sting; however, there has been no reported case due to catheters5. We report this as a rare case of a foreign body reaction caused by a retained cuff from a central venous catheter.