CEACAM5 and neoplasm: SCC components express p63 or p40,[6,7] while p53 overexpression is often observed in both components.[6] Although adenoid (acantholytic) SCC may mimic ASC due to the acantholysis (gland-like space) of the tumor cells, it is easily diagnosed because the tumor does not express CK7 and CEA.[6] Basaloid SCC and conventional SCC can also be diagnosed by the presence of tumor cells without a glandular malignant component.[1] On the other hand, differential diagnosis of mucoepidermoid carcinoma is difficult, because immunohistochemical analysis cannot generally distinguish it from ASC.