Nonsquamous cell malignant tumours of the oral cavity: an overview.

Many malignant tumours other than squamous cell carcinoma may present in the oral cavity. Melanomas of the oral cavity are usually pigmented, aggressive tumours associated with a poor prognosis. Neoplasms of the minor salivary glands have a greater tendency to be malignant than those of the major glands, and some exhibit a predilection for occurring in the mouth. Many types of connective tissue malignant tumours (sarcomas) may arise in the mouth, including soft-tissue cancers and lesions of hematologic cells such as lymphoma, whereas osteosarcoma is the most common malignancy of the hard tissues found in the mouth. Cancers from distant organs such as breast, lung and prostate may metastasize to the oral cavity. This paper presents a brief overview of nonsquamous cell oral cancers, with emphasis on those most likely to be encountered by the practising dentist.