A Glandular Odontogenic Cyst Mimicking a Dentigerous Cyst: A Diagnostic Pitfall.

Glandular odontogenic cysts (GOCs) are rare developmental odontogenic cysts that may pose significant diagnostic challenges due to their overlapping clinical and radiographic features with other odontogenic lesions. We report a case of a 29-year-old woman who presented with pain and restricted mouth opening associated with an impacted right mandibular third molar. Cone-beam computed tomography revealed a well-defined pericoronal radiolucency attached to the crown of the impacted tooth and extending to the distal root of the adjacent second molar. Based on the characteristic pericoronal location and apparent attachment at the cemento-enamel junction, a provisional diagnosis of a dentigerous cyst was made. Surgical enucleation of the lesion and extraction of the associated tooth were performed. Gross examination demonstrated continuity between the cystic lining and the cervical region of the tooth. Histopathological evaluation revealed a non-keratinised odontogenic epithelial lining of variable thickness with epithelial plaque-like thickenings, intraepithelial microcysts, superficial eosinophilic cuboidal (hobnail) cells exhibiting apocrine snouting, clear cells, and ciliated cells, consistent with a definitive histopathological diagnosis of a GOC. This case is notable because the dentigerous relationship was consistently demonstrated radiographically, grossly, and microscopically, yet the lesion exhibited definitive histopathological features of a GOC. The findings highlight the limitations of relying solely on clinicoradiographic features, including attachment at the cemento-enamel junction, for diagnosing pericoronal lesions. Careful histopathological assessment remains essential for distinguishing GOCs from dentigerous cysts and other lesions with overlapping features, ensuring accurate diagnosis and appropriate management.