Adenoid cystic carcinoma(ACC) is an uncommon tumor of the head and neck. It is one of the most common malignant tumor of the salivary glands. Although ACC has clear pathologic features, it can be diagnosed as a benign lesion in terms of cytological and radiologic aspects. In this paper, we report a rare case of ACCACC on tongue that is diagnosed as ACC but appears as a benign lesion in cytological and radiologic views.

Lysyl oxidase (LOX) family, the copper dependent amine oxidase, oxidizes lysine residues in extracellular collagen and elastin. LOX increases the strength of the extracellular matrix and plays an important role in tumor development and metastasis. It has been reported that increased LOX protein and RNA are found in head and neck squamous cell carcinoma. Moreover some studies regarded LOX as a prognostic marker of oral and oropharyngeal squamous cell carcinoma. However there has not been any report on LOX expression of salivary gland tumors. Here, we investigated LOX expression in mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) of salivary gland and compare it to those of pleomorphic adenoma (PA). We evaluated LOX expression in eighteen MEC, eighteen ACC and twenty PA cases by immunohistochemical examination. Whereas PA showed relatively low density of LOX expression, ACC revealed more cases that showing high staining intensities for LOX. Significantly increased LOX expression was found in the cases of ACC when compared to those of PA (P = 0.010).