A Radicular Cyst and an Aneurysmal Bone Cyst Converging in the Maxilla: A Concurrent Encounter.

We present a unique case of a patient in early adolescence presenting with swelling in the upper left back region of the jaw, attributed to a failed root canal treatment of the upper left first molar. Clinical and radiographic assessments led to a preliminary diagnosis of a radicular cyst. Surgical enucleation revealed unexpected findings, with a steady ooze of blood encountered from one side of the lesion and the retrieval of an epithelial lining from the other side. Histologic examination confirmed the presence of both a radicular cyst and a secondary aneurysmal bone cyst (ABC). To the best of our knowledge, this is the first reported case of an ABC of the maxilla coexisting with a radicular cyst. This case underscores the importance of thorough evaluation and histological examination in cases of suspected cystic lesions, as well as the potential for unexpected findings and coexisting pathologies.