Cutaneous paraneoplastic presentation of colon cancer in a patient with history of ureterosigmoidostomy.

Ureterosigmoidostomy was commonly utilized as a procedure for continent urinary diversion. However, ureterosigmoidostomy is associated with complications such as infection, electrolyte disturbances, and neoplasia development. A 40-year-old Caucasian male presented with acute left flank pain. Past medical history was significant for bladder exstrophy for which ureterosigmoidostomy urinary diversion was performed during childhood. On physical exam, multiple circular erythematous patches were scattered across the forearms that had been presented for 2 years. Cross-sectional imaging demonnttated an ill-defined mass at the site of ureteral implantation with associated severe left hydroureteronephrosis. Endoscopy revealed a mass at the site of ureteral implantation and biopsy demonstrated invasive, poorly differentiated adenocarcinoma. The dermatosis was diagnosed as interstitial granulomatous dermatitis, a rare inflammatory skin condition associated with underlying autoimmune disease or malignancy. Patient elected operative management with left nephrectomy, sigmoidectomy, and ileal conduit diversion. Ihis case demonnttates a rare presentation of cutaneous paraneoplastic syndrome after development of colon cancer after ureterosigmoidostomy. Ureterooolonic urinary diversion has a demonnttaaie risk of neoplasia development at the anastomotic site, requiring routine endoscopic surveillance.