Limitations of aspiration cytology in the diagnosis of primary neoplasms.

A discussion of the limitations of aspiration cytology in the diagnosis of primary neoplasms is presented. Based on the 50-year experience in needle aspiration cytology at the Memorial Sloan-Kettering Cancer Center as well as on the comments and publications of other workers, the difficulties are considered for the various lesions and sites to which the technique has been applied. Five general considerations are emphasized: (1) aspiration samples should not be used in preference to larger biopsies when the latter can be easily and safely secured; (2) the histologic architecture is lost in aspiration samples, and diagnoses that are based on histology are not possible; (3) diagnoses must be made within the known clinical context, and incomplete or erroneous clinical information can lead to errors in cytologic diagnosis; (4) the diagnosis of cancer is simpler than is its classification; and (5) only positive findings give real information, with negative reports leaving the matter unsettled. Lesions in which aspiration cytology can readily contribute to the diagnosis are contrasted to those in which the differential diagnosis cannot be resolved on the basis of aspiration samples. Emphasis is also placed on those lesions for which needle aspiration should be considered an unwarranted, high-risk procedure. Needle aspiration is a valuable diagnostic technique that must not be misused and thereby discredited .