Liver metastases from maxillary sinus sinonasal undifferentiated carcinoma: A case report.

Sinonasal undifferentiated carcinoma (SNUC) is a rare malignancy arising from the nasal cavity with neuroendocrine differentiation and aggressive behavior. When first diagnosed, SNUC is often locally advanced with nodal and distant metastases. The present study indicates a rare case of sole metastases to the liver from maxillary sinus undifferentiated carcinoma. Diagnosis was confirmed by total body computed tomography and immunohistochemical analysis on tissues from both maxillary and liver neoplastic tissues. SNUC is an aggressive malignancy characterized by a poor prognosis. Distant metastases commonly involve bones and lungs and should always be suspected in patients with locally advanced stages. Distant metastases can be found in unexpected organs due to dissemination via collateral venous plexuses; isolated liver metastatic disease may also occur. Although SNUC is considered a chemo-sensitive malignancy, chemotherapy for metastatic SNUC needs to be further explored.