An unusual case of adenoid cystic carcinoma presenting with isolated liver metastasis: A case report

Adenoid cystic carcinoma (ACC) is a rare, slow-growing malignant tumor of the salivary glands characterized by perineural invasion and delayed distant metastasis. While pulmonary and osseous metastases are common, isolated hepatic metastasis as the initial presentation is exceptionally rare and diagnostically challenging.

A 70-year-old female presented with right hypochondrial pain and an epigastric burning sensation. She had a long-standing, painless swelling in the right submandibular region for over 10 years, for which she had not previously sought medical evaluation.

Imaging revealed a solitary hepatic mass measuring 11 cm × 11 cm × 9 cm involving segments IV, VII, and VIII with vascular involvement. Histopathology of the liver biopsy showed basaloid cells arranged in cribriform and tubular patterns within a myxoid stroma. Immunohistochemistry demonstrated CK7 and cluster of differentiation 117 positivity in luminal cells and SMA and p63 positivity in abluminal cells, confirming ACC. Fine needle aspiration of the submandibular swelling showed features consistent with ACC, establishing the diagnosis of metastatic ACC to the liver.

Further imaging and oncologic consultation were undertaken. Surgical resection was not feasible due to the tumor size and vascular involvement. Chemotherapy was offered.

The patient declined further treatment after counseling regarding the metastatic nature of the disease and the potential treatment burden.

Isolated liver metastasis as the initial manifestation of ACC is exceedingly uncommon. Histopathology and immunohistochemistry are essential for diagnosis. Long-term follow-up is crucial due to the risk of delayed distant metastasis and the lack of standardized management guidelines.