Adenoid cystic carcinoma of the lung: Interest of 18FDG PET/CT in the management of an atypical presentation

Adenoid cystic carcinoma (ACC) is a common head and neck tumor originating from salivary glands but that can also exceptionally develop in the trachea and major bronchi. ACC is generally considered as a slow-growing, low-grade malignancy with prolonged clinical course. Metastases are very unusual and recurrences are more often local. Treatment for localized ACC is surgery. We here report for the first time a case of lung ACC with a synchronous liver metastasis proved by biopsy. Moreover, we report the interest of performing a 18FDG PET-CT as both primary tumor and liver metastasis presented an intense FDG uptake. The specificity of the liver 18FDG uptake was confirmed by Glut-1 positive immunostaining. We propose that 18FDG PET-CT should be considered in the initial staging of lung ACC in selected patients.