SALIVARY GLANDS AND SALIVA Number 9 Salivary gland tumours

Summary and conclusions Salivary gland neoplasms are a diverse and difficultgroup of tumours, which are best treated withinspecialist centres. Even the most common benignneoplasms – especially pleomorphic adenoma – needcarefulsurgicalmanagementandfollow-up.Becauseofthe morphological diversity both between and withintumour types, the gold standard for diagnosis remainscareful histological examination of an excised speci-men. Diagnosis on small incisional biopsies may beimpossible, especially in the case of clear cell tumoursand in differentiating between polymorphous adeno-carcinoma, pleomorphic adenoma and adenoid cysticcarcinoma.Although the current classifications for salivarygland tumours appear to be unnecessarily complexthey are essential for pathologists to provide a precisediagnosis. Careful use of established terminology hasallowed accurate reporting of case series and theprospective accumulation of prognostic information.Overtimethishasenabledtumourtypestobegroupedinto grading categories, which act as a useful guide tobehaviour.Grading of individual tumours, however, isdifficult and has only been shown to be useful inadenocarcinomaNOS,mucoepidermoidcarcinomaandadenoid cystic carcinoma. Polymorphous low gradeadenocarcinoma,forexample,islabelledaslowgrade,butitsbehaviourisunpredictableandrecentexperienceshows that it does not do as well as other low gradelesions. There no longer seems to be any justificationforthistumourtobetheonlysalivaryglandneoplasmwith a statement of grade to be included in thename.Thisneoplasmshouldberenamedpolymorphousadenocarcinoma.