A diagnostic dilemma: endodontic lesion or odontogenic keratocyst? A case presentation.

AIM: To present a clinical case of odontogenic keratocyst (OKC) simulating a lateral periodontal cyst. SUMMARY: A 39-year-old female complaining of swelling and pain in the left mandibular premolar area was found to have a radiolucent lesion between teeth 34 and 35 (FDI). Both teeth had incomplete root fillings, and orthograde re-treatment of both premolars was performed. At 2-year follow-up, radiographic examination showed an increase in the radiolucent defect with respect to the previous examination. A surgical treatment of tooth 34 was then performed, with histological examination of the lesion. Histological features were consistent with an OKC, and the lesion was successfully treated by complete enucleation and application of Carnoy's solution. At 2-year follow-up, no clinical signs or symptoms were found and the radiolucent area had disappeared. KEY LEARNING POINTS: Odontogenic keratocysts may mimic endodontic lesions. Clinicians should carefully review their cases and consider surgical intervention with biopsy in cases that do not heal.