Solitary Metastasis of Adenocarcinoma of Submandibular Gland to Choroid Plexus in Cerebellopontine Angle: First Case Reported in Literature

Adenocarcinoma of the salivary gland (AdCASG) is a rare and malignant tumor of the salivary glands. Albeit, metastatic lesions occur anecdotally in the choroid plexus and most rarely in the cerebellopontine angle (CPA). We report the first case of metastatic AdCASG to the choroid plexus of the lateral recess of the fourth ventricle located in CPA, emphasizing the clinical presentation and neuroradiologic findings. A 40-year-old man was referred with signs of increased intracranial pressure and a unilateral hearing problem. Magnetic resonance imaging showed a pear-shaped, vividly enhancing tumor in the left CPA. The tumor was a metastatic AdCASG. Gross total resection of the lesion was followed by a conventional radiotherapy lead in a 5-year tumor-free control interval. Metastatic lesions to the choroid plexus may show a pedunculated shape in magnetic resonance imaging. It is hypothesized that tumor seeding may occur through the veins, lymphatics, and nerve sheaths in the skull base region. Tissue specimen is necessary to confirm such rare pathology.