A mucinous adenocarcinoma of the lip with elevated serum carcinoembryonic antigen levels: a case report

Background Mucinous adenocarcinoma (MAC) rarely occurs in the salivary glands, especially in the labial gland. MACs arising from the salivary glands are characterized by an aggressive behavior due to high invasiveness and a high rate of regional lymph node metastasis. Case presentation Here, we report a case of MAC arising from the lower lip, shown to have elevated serum carcinoembryonic antigen (CEA) levels by the medical checkup. The tumor showed aggressive behavior and serum CEA levels increased with repeated recurrence. CEA has been shown to have surprisingly diverse functions in cell adhesion, intracellular and intercellular signaling, and complex biological processes such as cancer progression, inflammation, angiogenesis, and metastasis. A MAC arising from the salivary glands may have a poor prognosis because CEA is highly expressed. Conclusions Generally, serum CEA levels have not been used as tumor markers for salivary gland malignancies; however, it may be useful for MAC arising from salivary glands. We recommend prospective research to determine whether serum CEA estimation is useful as a component of routine pre-treatment workup for MACs arising from the salivary glands.