Leuchtenberger bodies in flat adenomas of the colorectal mucosa: a comparison between Japanese and Swedish patients.

The dysplastic epithelium of flat colorectal adenomas was found to contain DNA inclusion granules, known as Leuchtenberger bodies (LB). Hematoxylin and eosin-stained sections of 263 colorectal flat neoplastic lesions (i.e., flat adenomas, and flat adenocarcinomas) collected in Japan and Sweden were scrutinized for the presence of such intraepithelial inclusions. LB were recorded in 87.1% of the 263 flat colorectal neoplastic lesions. The frequency of flat colorectal lesions having LB was similar in Japan (160 of 178 or 89.8%) to that in Sweden (69 of 85 flat lesions or 81.2%), suggesting that the occurrence of LB may not be influenced by race or environment. Direct immunoperoxidase detection of nuclear DNA fragmentation and transmission electron microscopy studies indicated that the inclusions contained apoptotic material. The semiquantitative assessment of histochemically labeled apoptotic granules indicated that the number of lesions having moderate to large numbers of apoptotic granules (++/ ) was higher in flat adenomas with high-grade dysplasia, suggesting that the occurrence of these granules may be related to the degree of severity of the dysplastic process. A better knowledge of LB may improve our understanding of the possible relationship between apoptosis, host immune response and carcinogenesis in flat colorectal adenomas.