Periapical radiolucency mimicking an odontogenic cyst.

AIM: To present a clinical case of a giant cell lesion located in an unusual site, initially misdiagnosed and treated as an odontogenic cyst.

SUMMARY: Periapical radiolucencies often suggest the presence of odontogenic pathosis, usually inflammatory granulomas or cysts. The high frequency of such lesions tends to lead clinicians to arrive at a diagnosis without completing a comprehensive assessment of the patient or carrying out the full range of available diagnostic tests. A case report of a giant cell lesion, which was misdiagnosed and treated initially as an odontogenic lesion because of its unusual location, is presented.

KEY LEARNING POINTS: Clinical signs and radiographic appearance are usually sufficient to reach a diagnosis of periapical pathosis. When traditional treatment does not lead to success, a biopsy should be considered to ascertain the diagnosis and allow the correct treatment to be provided. Histological examination of soft tissue removed during endodontic surgery is essential.