<p>Glandular odontogenic cyst (GOC) is a rare odontogenic cyst characterized by distinctive epithelial features and is known for its potential for local aggressiveness and recurrence. Because its clinical presentation and imaging characteristics substantially overlap with those of other odontogenic cysts and tumors, establishing a preoperative diagnosis is often challenging, and a definitive diagnosis relies on histopathological evaluation. We report the case of a 46-year-old man in whom panoramic radiography, computed tomography (CT), and magnetic resonance imaging (MRI) failed to yield diagnostic specificity, and who was ultimately diagnosed with GOC based on histopathological examination. Panoramic radiography revealed a multilocular radiolucent lesion extending from the right mandibular body to the right mandibular ramus. Unenhanced CT images demonstrated lingual cortical thinning with focal discontinuity and buccal cortical thinning that was largely preserved. MRI showed a relatively homogeneous intermediate signal on T1-weighted images and a layered appearance on T2-weighted images, characterized by homogeneous high signal intensity superiorly and heterogeneous intermediate-to-high signal intensity inferiorly; however, none of these findings were specific to GOC. The lesion was removed en bloc under general anesthesia. Histopathological examination revealed features consistent with glandular odontogenic cyst, including non-keratinized stratified squamous epithelium of variable thickness with cuboidal cells, as well as mucous and clear cells, leading to a definitive diagnosis. This case highlights the diagnostic difficulty of GOC based solely on clinical and radiographic findings and underscores the indispensable role of histopathological assessment in establishing a definitive diagnosis.</p>