Diagnosis of mandibular metastatic tumour leading to findings of advanced lung carcinoma: A case report

Tran, C.; Napier, S.; Marley, J.

Background: Due to their low prevalence and variable clinical presentation, oral metastatic tumours present a diagnostic challenge to the clinician. This case describes the presentation of a mandibular metastatic tumour in an apparently healthy patient, initially managed as dento-alveolar infection by her general dental practitioner (GDP). Case description: A 56-year-old female attended her GDP with a small intraoral swelling buccal and lingual to the lower left incisors, canine and first premolar. Radiographic examination revealed gross caries in the lower left anterior dentition and periapical bone loss in the region. A week's course of antibiotics had no effect. The swelling increased rapidly and the involved teeth were extracted by the GDP before referral to Oral Surgery. The patient offered no history of weight loss, febrility or breathlessness. Her medical history was unremarkable. She smoked and did not consume alcohol. Histological examination revealed a poorly differentiated metastatic carcinoma. A computerized tomography scan of the neck showed a 4 cm mass in the left anterior mandible with adjacent bony destruction. There was bilateral cervical lymphadenopathy and a large right-sided upper lobe lung mass with metastasis to the contralateral upper lobe of the lung, the right adrenal gland and brain. A diagnosis of poorly differentiated non-small cell carcinoma of the lung was made, staged T4 N3 M1c. Nine weeks after her initial presentation to the GDP, the patient suffered a seizure and passed away. Conclusion: This case demonstrates an uncommon presentation of mandibular metastatic tumour as the first indicator of advanced malignant disease. The presentation of such tumours can often mimic more common, benign processes, making diagnosis challenging. At a time of increased remote assessment of patients due to the COVID-19 pandemic, it is particularly important for clinicians to consider the possibility of malignancy when faced with any unusual case of swelling. © 2021 British Association of Oral Surgeons and John Wiley & Sons Ltd.