Management of Extensive Hepatic Metastases From Adenoid Cystic Carcinoma of the Parotid Gland by Embolization and Hemi-Hepatectomy: A Case Report

Adenoid cystic carcinoma (ACC) is a rare malignancy of the salivary glands characterized by slow growth, perineural invasion, and a predilection for distant metastasis, primarily to the lungs and bones. Liver metastasis from ACC is uncommon and poses significant diagnostic and therapeutic challenges. This report presents a case of mixed type of ACC (predominantly cribriform and tubular architecture with a solid component of 20%) originating in the parotid gland with multiple liver metastases from a tertiary center in India. A 32-year-old woman initially underwent a total conservative parotidectomy with facial nerve preservation and adjuvant radiotherapy for ACC of the right parotid gland in 2017. Immunohistochemistry was positive for CD117, S100, and smooth muscle actin (SMA). Following a recurrence of metastatic neck lymph node involvement in 2020, she underwent right modified radical neck dissection and additional radiation therapy. In 2024, surveillance imaging revealed liver lesions, confirmed as ACC metastases by biopsy with immunohistochemistry. Due to inadequate hepatic reserve for a right hemi-hepatectomy, a right portal vein embolization was performed to induce hypertrophy of the left liver. Subsequent right hemi-hepatectomy with segment II metastatectomy achieved an R0 resection, and the patient experienced an uneventful recovery. She remained disease-free six months postoperatively. ACC accounts for 1%-2% of all head and neck cancers and exhibits distinct clinical and pathological features. Its treatment is centered on surgical resection with adjuvant radiotherapy, although the efficacy of chemotherapy is limited. Liver metastasis, though rare, can be managed with surgical intervention in selected cases, potentially improving survival outcomes. This case underscores the importance of long-term follow-up for ACC patients due to the risk of delayed distant metastases. It also highlights the role of multidisciplinary management and individualized treatment strategies in achieving optimal outcomes in rare and complex clinical scenarios.