Hernia post-operative repair problems are infrequent and easily managed, but plug migration can be a more complicated event. Mesh plug migration is very uncommon and rarely presents as a suspected malignancy. We document a case involving a 79-year-old woman who exhibited a complex right-sided cystic mass that was presumed to be an adnexal malignancy. However, following surgery, the retroperitoneal mass was actually a PerFix mesh plug that migrated from an initial hernia surgery.