Volume 18, Number 4Case ReviewGossypiboma Manifesting as Urachal MassNirmish SinglaAhmed Q HaddadChristopher CefaluVitaly MargulisGossypiboma (retained surgical sponge) occurs between 1 in 1000 and 1 in 1500 of all intra-abdominal operations. Patients with gossypibomas may present asymptomatically or with nonspecific symptoms, such as abdominal pain or bloating; identification frequently relies on imaging. Results of imaging alone, however, may appear nonspecific, and the gossypiboma may mimic other masses, such as neoplasms, hematomas, or abscesses. They require surgical removal for definitive diagnosis and treatment. Herein we present an unusual case of gossypiboma masquerading as an urachal mass in a 75-year-old woman. Diagnostic evaluation, natural history, and prevention of retained surgical materials are discussed. [Rev Urol. 2016;18(4):239-241 doi: 10.3909/riu0703] © 2016 MedReviews®, LLCGossypibomaUrachal massSurgical errorsPatient safety