Central adenoid cystic carcinoma of the mandible manifesting as an endodontic lesion

Aim To present a case of adenoid cystic carcinoma (ACC) in the mandible, and manifesting as a periapical lesion. Summary A 56-year-old male suffered from pain around the right mandibular first molar for approximately 1 week. Oral examination revealed that the involved tooth was restored by a full coverage crown with no obvious abnormalities. A periapical radiograph revealed two ill-defined radiolucencies associated with the tooth, one over the mesial and another over the distal roots of the tooth; incomplete root filling and furcation involvement also being noted. The affected tooth was extracted based on the clinical impression of apical periodontitis. The surrounding tissue of the root apex was curetted and sent for histopathological examination, which revealed ACC. Key learning points Adenoid cystic carcinoma affecting the mandible may mimic a periapical lesion. Proper diagnosis of such a lesion is dependent on thorough clinical, radiographic and microscopic examinations. Such a case highlights the benefits of biopsy and histological examination of collected tissues. Diagnosis of lesions in the mandible should include salivary gland tumours.