A CASE OF PSEUDOMYXOMA PERITONEI WITH A CYSTIC TUMOR IN THE RETROPERITONEAL CAVITY WHOSE DIAGNOSIS OF THE PRIMARY LESION WAS DIFFICULT

A 51-year-old woman was seen at the hospital because of a right abdominal mass and abdominal distension. She was diagnosed as having a pseudomyxoma peritonei and operated on. At operation, there was a cystic tumor in the right retroperitoneal cavity which was occupied with gelatinous material, and it was infiltrating into the abdominal cavity where a large quantity of same material also existed. We could not abrade the cystic tomor from the ascending colon. There were a few nodules at the sigmoid colon that were considered the dissemination. The appendix was difficult to be identified because of a previous history of undergoing an appendectomy. Right hemicolectomy including the cystic tumor, sigmoidectomy, omentectomy, bilateral oophorectomy and intraperitoneal lavage with 5% glucose were performed. Then cisplatin 100mg was infused into the abdominal cavity. Microscopic examination of the cystic tumor showed mucinous cystadenoma. After the operation, intraperitoneal lavage was performed many times and cisplatin 200mg was infused into the abdominal cavity through a reservior. During the same period, chemotherapy with 5-FU was also given to the patient. This paper presents a rare case of pseudomyxoma peritonei with a main tumor in the retroperitoneal cavity, together with a review of the literature.