Aspiration cytology of salivary glands.

Although mass lesions of the salivary glands are readily accessible to examination by fine-needle aspiration, the use of this modality has been limited. In part, this may be related to the difficulty differentiating between benign and malignant neoplasms in some cytologic specimens. Marked atypia in reactive non-neoplastic epithelium also could result in a false-positive diagnosis. In addition, aspiration of hypocellular material from cystic neoplasms, eg, well-differentiated mucoepidermoid carcinoma, may lead to false-negative cytologic reports. However, the diagnostic specificities claimed by a number of authors for this method are excellent. Furthermore, aspirates of certain specific neoplasms may yield highly distinctive cellular samples, such as the uniform tumor cells and extracellular hyaline spheres in many adenoid cystic carcinomas. Another example is the characteristic transition between the epithelial and myoepithelial cells of pleomorphic adenomas, which may contain prominent myxoid matrical material. With the increasing recognition of such features, the reported levels of diagnostic accuracy are improving.