Not all abdominal masses after colorectal cancer surgery are malignant: intra-abdominal fibromatosis masquerading as recurrence

Summary

Our aim was to determine the incidence of fibromatosis in a cohort of patients undergoing cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy (HIPEC) for suspected colorectal cancer recurrence. 171 CRS and HIPEC cases were performed at our Peritoneal Malignancy Institute between February 2007 and October 2018 for colorectal peritoneal metastases and were included in a prospectively maintained database. A total of 49 out of 171 cases (29%) were performed for primary colorectal cancer with peritoneal metastases, whereas 122 of 171 cases (71%) were performed for suspected colorectal cancer recurrence detected on surveillance imaging after primary colorectal cancer resection. On histological analysis of the resected specimen, 5 out of 122 (4.1%) cases undergoing CRS and HIPEC for colorectal recurrence had fibromatosis. Fibromatosis can masquerade as colorectal cancer recurrence. In this series it occurred with an incidence of 4.1% among a cohort of patients undergoing CRS and HIPEC for probable recurrence. Surgical resection may be the only option to confirm the diagnosis and rule out malignancy.