A case report of idiopathic systemic capillary leak syndrome that occurred during the postoperative period of abdominoperineal resection for colorectal cancer.

A 57-year-old woman without any past medical history underwent abdominoperineal resection for rectal cancer in our department. On postoperative day 15, the patient complained of sudden abdominal pain, and high fever was noted in addition to the appearance of erythema around the stoma. The diagnosis of phlegmon was made, and antibiotic infusion was started. However, a few days later, the patient developed hypovolemic shock with hypoalbuminemia and hemoconcentration. Fasciotomy was performed to exclude the necrotizing fasciitis, though all cultures were negative. Upon exclusion of the differential diagnoses, idiopathic systemic capillary leak syndrome (ISCLS) was diagnosed. She was successfully treated with massive fluid infusion under ventilation and continuous hemodiafiltration. Here, we report the first case of ISCLS that occurred during the postoperative period of colorectal surgery.