Semiquantitative analysis of the cellular preservation quality of Normosol and Carbowax solutions for thyroid fine-needle aspiration specimens.

The present study was designed to compare cytomorphologic features and diagnostic value of thyroid fine-needle aspiration (FNA) specimens stored in Saccomano's (Carbowax(R) solution) fixative and Normosol(R) solutions. Equivalent amounts of aspirate material obtained from nonlesional areas of 17 freshly resected thyroidectomy specimens were placed in room temperature Carbowax(R) solution and refrigerated Normosol(R) solution for a time period of up to 60 hr. Millipore(R) filter preparations were made from both fluids for each of the 17 thyroidectomy specimens. Slides were examined by three independent observers who rated the quality of cellular preservation based on a four-part semiquantitative scale. Statistical analysis of the data obtained from the scores of the three observers showed no statistically significant difference in the quality of specimen preservation. Normosol(R) preserved specimens consistently rated superior to Carbowax(R) in nuclear detail, lack of obscuring background artifact, and diagnostic value. These findings, along with a considerably less cost, make refrigerated Normosol(R) an attractive alternative for the short-term storage of FNA specimens placed in fluid.