LOW-GRADE MUCOEPIDERMOID CARCINOMA ON THE VERMILION BORDER OF THE LIP

We report a case of primary cutaneous carcinoma with mucoepidermoid fe atures located on the vermilion border of the lower lip, at a distance from both salivary glands and cutaneous adnexal structures. The clini cal appearance of the present case, which is similar to that of conven tional cutaneous squamous cell carcinoma, as well as the existence of surrounding areas of actinic cheilitis favors the hypothesis of a phen omenon of mucinous metaplastic change in a squamous cell carcinoma. We consider that, independently of their origin, tumors having mucin-sec reting and squamous differentiation ought to be named according to the same criteria generally used for other organs, namely, ''low grade mu coepidermoid carcinoma'' would designate tumors with bland mucin-secre ting cells and well-differentiated squamous component, and ''high grad e mucoepidermoid carcinoma'' would indicate their less well differenti ated counterpart. We propose to reserve the term ''adenosquamous carci noma'' for aggressive tumors with high-grade glandular and squamous el ements, marked nuclear atypia, frequent mitoses, and extensive necrosi s.