title: Oxidized regenerated cellulose granuloma mimicking recurrent mass lesion after laparoscopic nephron sparing surgery.
abstract: BACKGROUND
  Achieving hemostasis in laparoscopic nephron sparing surgery (LNSS), a technically demanding procedure, is challenging. Absorbable hemostatic agents, such as oxidized regenerated cellulose (ORC) are frequently used for hemostasis in laparoscopic nephron sparing surgery. Retention of this material is a very rare situation.
  
  
  METHODS
  We are presenting a case of ORC granuloma after nephron sparing surgery for renal cell carcinoma (RCC) mimicking recurrent renal mass. A 50-year-old woman diagnosed with upper pole renal mass underwent laparoscopic nephron sparing surgery. Oxidized regenerated cellulose was used to achieve hemostasis for an oozing from the perirenal tissue. Resection confirmed RCC. Imaging at 6th month follow-up revealed a lesion with contrast enhancement at the location of the adrenal gland. Positron emission tomography suggested inflammation or metastasis. Histopathological evaluation of the mass revealed foreign body granuloma.
  
  
  CONCLUSIONS
  Laparoscopic nephron sparing surgery is becoming a standardized treatment of select renal tumors. Hemostatic agents, such as ORC, are frequently used to minimize complications in LNSS. In case of ORC application, which is completely absorbed in 8 weeks, to or to a location with close proximity to the primary resection site, surgical granuloma formation should be considered. However its use should not be discouraged and biopsy may be considered for definitive diagnosis.
  
  
  CONCLUSIONS
  Oxidized regenerated cellulose granuloma may mimic different entities such as including invasive carcinoma. Thus it is of utmost importance, if ORC was used during LNSS, the location and use of this material should be noted precisely.
authors.affiliation: Department of Urology, Istanbul Faculty of Medicine, Istanbul University, Turkey.
authors.forename: Tzevat
authors.initials: T
authors.lastname: Tefik
authors.forename: Oner
authors.initials: O
authors.lastname: Sanli
authors.forename: Tayfun
authors.initials: T
authors.lastname: Oktar
authors.forename: Omer Baris
authors.initials: OB
authors.lastname: Yucel
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Ozluk
authors.forename: Isin
authors.initials: I
authors.lastname: Kilicaslan