Atypical mitoses in dysplasias of the Barrett's mucosa.

The frequency of mitotic figures, the proportion of atypical mitoses, and the spatial position (vertical or horizontal) of metaphasal plates were studied in resected specimens from 18 patients having Barrett's mucosa with dysplasia, and/or invasive adenocarcinoma. The number of dividing glandular cells increased (by comparison with the non-dysplastic Barrett's mucosa) in areas with dysplasia and with invasive adenocarcinoma, the largest percentage was found in the latter. Atypical mitoses were often found in areas with glandular dysplasia and with invasive adenocarcinoma. The highest frequency was found in adenocarcinoma. While 90.8% of the metaphases in Barrett's mucosa without dysplasia had a vertical position, only 39.5% of the mitoses in areas with dysplasia had the same position. It is conceivable, that the number of mitoses, the number of atypical mitoses as well as the spatial position of mitosis should be registered in the Barrett's mucosa with dysplasia in attempts to learn more about the biological behaviour of these lesions.