Anterior lingual mandibular salivary gland defect (Stafne defect) presenting as a residual cyst

Lingual mandibular salivary gland inclusion (Stafne defect) is a developmental anomaly represented by a bone concavity usually containing submandibular gland tissue. The posterior mandible region, particularly at the angle and below the mandibular canal, is the common location, and the anterior mandibular variants occur rather seldom. The latter is usually observed in the premolar and cuspid region, or more rarely in the symphysis, as a round or ovoid radiolucency sometimes appearing superimposed over the teeth's apices, resembling a true cystic lesion or an odontogenic tumor. We report an additional case of anterior lingual mandibular salivary gland defect occurring in a 42-year-old white man. It presented as an asymptomatic radiolucency located on the left side of the mandible, in the region of an absent second premolar and first molar, above the alveolar canal, mimicking a residual cyst. Histopathologic examination of the "cyst" content revealed the absence of a cyst lining and the presence of normal sublingual gland tissue.