Intra-abdominal fibrosis after systemic and intraperitoneal therapy containing fluoropyrimidines

Intra-abdominal and retroperitoneal fibrosis has been described as secondary to intraperitoneal (IP) administration of several chemotherapeutic agents, including carboplatin, mitoxantrone, and the combination of 5-fluorouracil and cisplatin. The IP administration of floxuridine (FUDR) is an effective and minimally toxic treatment for patients with metastases to the peritoneum. An increasing number of patients with colorectal, gastric, or ovarian carcinoma are treated with IP chemotherapy.

The authors report two patients with metastatic colon carcinoma who experienced severe intra-abdominal fibrosis presenting as an intra-abdominal mass mimicking recurrence in one patient and diffuse encasement of the bowel in the other, after the administration of IP FUDR and leucovorin.

Two patients with Stage III colon adenocarcinoma received postoperative adjuvant 5-fluorouracil and levamisole. They subsequently presented with a rise in carcinoembryonic antigen level and isolated liver metastasis. They underwent hepatic lobectomy with postoperative intra-arterial hepatic FUDR and systemic 5-fluorouracil and leucovorin. They each had an intra-abdominal recurrence, which was resected and treated with postoperative IP FUDR and leucovorin. They then presented with a diffuse pattern of IP fibrosis with no tumor identified.

IP FUDR and leucovorin therapy can be associated with diffuse IP fibrosis, which in this study caused an intra-abdominal mass that was indistinguishable from recurrent malignancy in one patient and encasement of the bowel in the other.