APPLICATION OF PLASTIC EMBEDDING TO FINE-NEEDLE ASPIRATION BIOPSY

OBJECTIVE: To explore the possible advantages that plastic embedding o ffers to fine needle aspiration biopsy (FNAB). STUDY DESIGN: A series of 54 FNABs teas fixed in Kryofix (30 cases) and acetone (24 cases), p lastic embedded and cut using a rotative microtome. The 2-mu m section s obtained were May-Grunwald-Giemsa and Papanicolaou stain in all case s; mucicarmine, Alcian Blue, periodic acid-Schiff (PAS), PAS-diastase and Feulgen stain for DNA cytometric evaluation were also applied in f ive cases. Immunocytochemical staining using the antibodies cytokerati n 1-8, epithelial membrane antigen, vimentin, Ki-67, lysozime, calcito nin and carcinoembryonic antigen was carried out with the immunoalkali ne phosphatase method. RESULTS: The fragments in the sections were per fectly two dimensional; the architectural features of the original tis sues were preserved. Morphologic details of nuclear membranes, nucleol i and mitotic figures were excellent. Cytochemical and immunocytochemi cal stains were successful in all cases. Immunostains showed the preci se location of the signal (nuclear, nucleolar or cytoplasmic), a clear background and preservation of morphology. CONCLUSION: Plastic embedd ing can be applied to FNAB to solve the problem of dense cellular grou ps, to study structural and cellular details, and to capitalize on the diagnostic material available for serial cytochemical, quantitative a nd immunocytochemical purposes.