Symptom control with lattice stereotactic body radiotherapy for hepatic metastasis from adenoid cystic carcinoma: A case report

Introduction Adenoid cystic carcinoma (ACC) is a rare and indolent malignancy characterized by delayed metastases. While pulmonary metastases are common, hepatic involvement is uncommon, with limited evidence guiding local treatment strategies. Case Presentation A 59-year-old gentleman previously treated with surgery and adjuvant radiotherapy for ACC of the floor of mouth presented three years later with dry cough and abdominal pain. Imaging demonstrated multiple bilateral pulmonary nodules and a large solitary hepatic lesion. Considering the history of primary ACC, the imaging raised suspicion for a new primary hepatobiliary malignancy; however, tissue diagnosis confirmed metastatic ACC. Despite radiologically stable disease following chemotherapy, the patient developed progressive abdominal pain from the hepatic lesion. Palliative lattice stereotactic body radiotherapy was delivered for symptom control. The hepatic lesion remained radiologically stable at 15 months with sustained symptomatic improvement, despite progression at extrahepatic sites. Conclusion This case highlights the rare and latent occurrence of hepatic metastasis in ACC and the importance of histological confirmation in atypical metastatic presentations. Lattice stereotactic body radiotherapy may provide durable local control and meaningful symptomatic benefit in selected patients.