Epidermoid Cyst in an Infected Olecranon Bursa.

Epidermoid cysts are common, benign cysts that form due to follicular epithelium implanting into the dermis. Although these cysts are often painless, they can incite an inflammatory process as well as abscess formation, especially if ruptured. Our case involves a 59-year-old woman with a history of remote elbow trauma diagnosed with septic olecranon bursitis with concomitant epidermoid cyst found on histology following incision and drainage (I&D). Due to the rare presentation and inadequate preoperative imaging, the diagnosis of epidermoid cyst was not made prior to surgery, resulting in incomplete enucleation.