Identification of hepatic metastasis from an unrevealed adenoid cystic carcinoma by PET/CT: A case report

Rationale:Adenoid cystic carcinoma is a rare malignant tumor of the salivary glands, with few reports of metastasis to the liver in the literature. We present a case where an isolated hepatic lesion of adenoid cystic carcinoma was identified using F-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT). Patient concerns:A 76-year-old male experienced abdominal pain and underwent an enhanced CT scan and magnetic resonance imaging, which revealed a liver mass. Subsequent F-18-FDG PET/CT identified hypermetabolic lesions in both the left and right lobes of the liver, suggesting malignancy, with no other abnormalities detected. Diagnoses:A liver biopsy confirmed the diagnosis of adenoid cystic carcinoma. Interventions:No intervention. Outcomes:Following confirmation of the diagnosis, the patient chose to discontinue treatment and was discharged. Lessons:Hepatic metastasis from adenoid cystic carcinoma may be detected before the identification of the primary lesion. F-18-FDG PET/CT plays a critical role in differentiating benign from malignant liver tumors, selecting potential biopsy sites, and assessing the extent of metastatic disease.