Malignant Transformation of Post-Nephrectomy Enterocutaneous Fistula: A Review of Literature

Background: Enterocutaneous fistula is an aberrant epithelialized communication between the bowel and the skin occurring mostly as a complication of abdominal surgery. Enterocutaneous fistula may present as chronically discharging sinus and like any other chronic non healing wound, malignant transformation has rarely been reported in such gastrointestinal fistula. Herein we report an additional case of malignant transformation of enterocutaneous fistula leading to duodenal mass. Case Presentation: A 50-year diabetic gentleman presented with a persistent draining sinus from his surgical site of right nephrectomy for 6 months with friable growth over the sinus opening which sheds off spontaneously to reappear again after a period. Investigations showed duodenal growth communicating to the right renal fossa and further to the skin surface in the lumbar region. Exploratory laparotomy was performed where a circumferential mass was noted in the second part of duodenum with perforation in the posterior wall. The perforation was seen to communicate with skin via fistulous tract. Postoperative biopsy of duodenal mass confirmed it to be well differentiated squamous cell carcinoma with transmural infiltration. Conclusion: When perirenal or retroperitoneal inflammation takes place, second part of the duodenum becomes involved and the absence of a protective peritoneal barrier between the two, along with the relative immobility of the duodenum, accounts for the internal drainage and fistula formation which occurs. Persistent enterocutaneous fistula after nephrectomy causes long standing pus discharge and malnourishment affecting the overall health of these patients. Chronic inflammation is known to be a risk factor for development of squamous cell carcinoma. Two previous cases of malignant transformation of post nephrectomy colocutaneous fistula have been reported. However, this case is unique as no prior reporting of malignant transformation of duodeno-cutaneous fistula was found in literature.