PERIPHERAL ODONTOGENIC KERATOCYST WITH PERIODONTAL GINGIVAL LOCALIZATION: DIFFICULTIES OF DIFFERENTIAL DIAGNOSIS AND DATA FROM LITERATURE

Introduction: In the literature, a variety of peripheral lesions exist, including rare variants of odontogenic lesions, which makes their differential diagnosis more challenging for clinicians and radiologists too. Among all of these, Odontogenic Keratocysts (OKCs) are benign cysts arising from the dental lamina’s remnants. OKCs are commonly located in the mandibular posterior body and ramus; their peripheral localization is noticeably rare. We report a case of peripheral OKC and also define the criteria for the correct differential diagnosis and treatment of such peripheral lesions; data from the literature are reported too.

Methods: A 68-year-old female patient was referred to the Complex Unit of Odontostomatology at the University of Bari “Aldo Moro” due to asymptomatic swelling of the right inferior vestibular gingiva. A radiograph revealed well-defined roundish radiotransparent evidence between elements #4.3 and #4.4. After local anesthesia, the elevation of a full-thickness flap revealed a cystic wall, whose rupture caused the release of a straw-colored fluid. Due to the uncertain diagnosis, the patient underwent complete surgical excision of the lesion and careful curettage of the cavity, including the adjacent dental roots. The specimen was sent for histopathological examinations.

Results: The histopathological report led to the diagnosis of a peripheral OKC. The patient underwent clinical–radiographical follow-ups every 3 months, showing complete healing of the osteolytic area. No complications or recurrence was detected.

Conclusions: The data from the literature highlight the rarity of peripheral OKCs, as only 33 cases have been reported to date. This herein-presented case shows how the wide variety and clinical aspects of peripheral lesions could be misleading for a differential diagnosis, which makes a histopathological examination both mandatory and exclusively diriment for the final diagnosis. The absence of pathognomonic features for both clinical and radiological diagnoses, combined with the possibility of an odontogenic extraosseous manifestation with high recurrence rates, makes a preventive and complete excision of peripheral lesions crucial for proper healing without recurrence.