Intra-abdominal cysts may arise from a variety of organs. However, foreign-body reaction and cyst formation should be considered in the differential diagnosis. In this report, we descibe the finding of a preoperatively undetected gossypiboma. A gossypiboma is a mass within the body that is composed of a cotton matrix; in this case, an unmarked laparotomy sponge. The evaluation, findings, and prevention of gossypiboma are discussed.
(Arch Surg. 1996;131:566-568)