Periapical central giant cell granuloma misdiagnosed as odontogenic cyst.

AIM To present the clinicopathological features of a series of four periapically located central giant cell granulomas (CGCGs) that were misdiagnosed and treated as being of endodontic origin. SUMMARY Four cases of periapical CGCGs were submitted with a clinical diagnosis of either radicular or residual cyst. In two cases, root canal treatment had been performed previously. The patients were two women and two men whose age ranged from 31 to 85 years. Two cases were located in the mandibular premolar-molar region, and two in the anterolateral region of the maxilla. Two lesions were submitted for histological examination with a diagnosis of radicular cyst whereas the remaining two were submitted with a diagnosis of residual cyst. KEY LEARNING POINTS Periapical giant cell lesions may be unilocular and therefore misdiagnosed as an endodontic lesion because of their radiographic similarity to an inflammatory periradicular lesion, especially if the teeth have been root filled or if the vitality is negative or doubtful. It is important to follow up the healing process of a periapical radiolucency related to a root filled tooth and, in case of persistence, to perform surgery and to submit the specimen for histological examination.