DETECTION OF TELOMERASE EXPRESSION IN FINE-NEEDLE ASPIRATIONS AND FLUIDS

The cytologic examination of fine-needle aspirates and fluid specimens is plagued by a persistent false negative rate. The rate of false neg ative results will be decreased if sensitive molecular assays carl he developed to detect cytologically malignant cells. The current study i nvestigated telomerase expression as a potential marker of malignancy, using the telomeric repeat amplification protocol (TRAP) in fine-need le aspirates and fluid specimens. TRAP was performed on 24 fine-needle aspirate and 24 fluid specimens from different body sites and of diff erent histological diagnoses. We found that 6 of 12 fine-needle aspira te specimens that were cytologically positive for malignant cells expr essed telomerase activity, while no specimens that were cytologically suspicions for malignancy, atypical, or negative tested positive for t elomerase activity. Of the fluid specimens, 4 of 6 cytologically posit ive cases and 1 of 18 cytologically negative cases expressed telomeras e. Seven of eight telomerase negative, cytologically positive specimen s contained only rare malignant cells in a very bloody background. Per ipheral blood contamination is a possible pitfall in the TRAP assay, a s applied in the current study, because the assay is standardized to p rotein concentration that may be derived from lysed red blood cells. W e conclude that with further technical refinement, the TRAP assay coul d become a useful adjunct in the cytologic examination of fine-needle aspirates and fluid samples. (C) 1998 Wiley-Liss, Inc.