Establishing differential diagnoses of simple bone cysts: a case series and literature review

Simple bone cysts (SBCs) are connective tissue-lined cavities within bone. They may be empty or may contain fluid. However, because they have no epithelial lining, they are not true cysts. The etiology of SBCs is unknown, although they may be a localized aberration that occurs during normal bone remodeling or metabolism. They are usually asymptomatic and appear on routine radiographs. Because of their lack of unique clinical and radiographic features, it is important to establish differential diagnoses between SBCs and other lesions of the jaws, especially radiolucent lesions. There is no reported evidence of a traumatic cause. SBCs may be misinterpreted when associated with atypical clinical and radiographic characteristics, in turn causing diagnostic and endodontic problems. We herein present three cases of SBCs that were once misdiagnosed as radicular cysts. The difficulty of diagnosis, treatment, controversies regarding terminology, and process of reaching a correct diagnosis are also discussed.