254 DOI: 10.1309/91PY0RBD9W8Y5GNX © American Society for Clinical Pathology Anatomic Pathology / TELOMERE AND TELOMERASE IN AAH AND BAC Telomere Length and Telomerase Expression in Atypical

A b s t r a c t Telomeres are located at the ends of every human chromosome and are subject to shortening at each cycle of cell division in cell senescence and early carcinogenesis. We examined the expression of telomeric DNA in 21 atypical adenomatous hyperplasias (AAHs) and 40 bronchioloalveolar carcinomas (BACs) measuring 2 cm or less in greatest diameter using fluorescent in situ hybridization and the expression of human telomerase reverse transcriptase (hTERT) messenger RNA (mRNA) in 35 AAHs and 37 BACs. The mean numbers of telomeric signals per nucleus were 5.0 in AAH and 7.4 in BAC, each significantly less than for normal cells (14.7; P <.0001), but the mean number of telomeric signals for AAH and BAC was not statistically different (P =.22)