Recurrent Odontogenic Keratocyst Mimicking Persistent Periapical Lesion in the Anterior Maxilla: A Case Report With 15-year follow up.

Odontogenic keratocysts (OKCs) are aggressive odontogenic cysts with a high recurrence rate, often presenting diagnostic challenges due to their ability to mimic common periapical pathologies. Although more prevalent in the mandible, maxillary OKCs, especially those resembling periapical lesions, are rare and prone to misdiagnosis. This report details the case of a patient who presented with persistent swelling and pus discharge from the anterior maxilla, initially misdiagnosed as a chronic apical abscess following root canal treatment. Despite multiple endodontic interventions, symptoms recurred. Clinical and radiographic examinations revealed a large periradicular lesion associated with Tooth #12 (FDI). Following endodontic surgery and soft tissue debridement, histopathological analysis revealed the lesion as an OKC. The patient initially remained asymptomatic postsurgery, but recurrence necessitated a maxillary resection 5 years later. Annual follow-ups over the subsequent 10 years showed no further recurrence. This case underscores the critical importance of including OKCs in the differential diagnosis of persistent periapical lesions, particularly in atypical presentations or cases unresponsive to conventional endodontic therapy. Thorough diagnostic investigation, including histopathological analysis, is essential for accurate diagnosis and definitive surgical management to prevent recurrence and improve patient prognosis, as is the importance of long-term follow-up. Moreover, our discussion of the literature highlights that OKCs in the anterior jaws may not be as uncommon as thought, and therefore should be considered in the differential diagnosis of periapical lesions.