Smearing techniques for the concentration of particles from fine needle aspiration biopsy

Fine needle aspiration biopsy of palpable masses yields a variety of specimens. Some are fluid, whereas others are semisolid; some contain numerous particles, whereas others contain no identifiable particulate fragments. Not surprisingly, no single smearing technique can reasonably be expected to provide good results with such a variety of specimens. This article describes a family of techniques, of which one or more are applicable to virtually any fine needle aspiration biopsy specimen. The techniques described and illustrated include the two-step, one-step, absorption, and watch-glass techniques.