[Spontaneous healing of retroperitonea fibroasis after successful therapy of sigmoid carcinoma].

In a 64 year old man sigma cancer was diagnosed unexpectedly during an operation for retroperitoneal fibrosis (histologically benign fibrosis), that had caused unilateral hydronephrosis. In the following hemicolectomy this tumor of the colon turned out to be a medium high grade adenocarcinoma (tumor staging pT2, pN1, DUKES C). Chemotherapy with 450 mg/m2 5-FU once a week and a concomitant therapy with laevamisol was added for 6 months. Computer-tomography revealed a significant reduction of the retroperitoneal masses already before induction of chemotherapy. One year after termination of chemotherapy retroperitoneal fibrosis was no longer detectable. The course of events makes us assume that the retroperitoneal fibrosis of our patient was paraneoplastic and therefore completely reversible by successful removal of the underlying tumor.