A Comparative Cytological Study of the Neoplasms of Animals and Plants

Abstract

In the study of the cytology of human and animal cancer the work of Hansemann is the first to receive the attention of the cytologist. The older cytological studies on various normal and pathological tissues of Virchow (1851), Eberth (1876), Arnold (1879), Martin (1881), Cornil (1886), Klebs (1889), Schottlander (1888) and others have been reviewed so often that no further mention need be made here. Hansemann (1890) calls attention to a number of cytological phenomena which he observed in epitheliomas, which he claimed to be distinctly characteristic of these overgrowths. He holds that while most of the cell divisions in the epitheliomas are normal, one finds a great number of tripartite or multipartite divisions. Hyperchromatic and hypochromatic mitoses appear in large numbers and monaster stages with a relatively small number of chromosomes are also to be found. The origin of the hyperchromatic nuclei is of interest, since it has been one of the most disputed points in the question of the cytology of cancer. Hansemann ascribes the origin of these cells to an asymmetrical division, i.e., the chromosomes are unequally distributed to the poles, so that one of the resulting daughter nuclei has more chromosomes than the other. In 1891–92–93 and 1902 Hansemann reported further cytological data to support his first contentions. In these he reports on twenty other cancers of the human, in which he studied especially the telophase stages in cell division in order to determine the nature and degree of inequality of the distribution of the chromosomes after division. Hansemann stresses the point that these asymmetrical mitoses are to be found in no other normal tissues nor in any other type of hyperplasia, inflammatory regenerative tissue, or even sarcoma and he concludes that this type of mitosis is diagnostic for carcinoma. In large cell, fast growing sarcoma, however, one finds hyperchromatic cells occasionally. Hansemann was unable to settle the question of the chromosome number in the somatic and germ cells in man. This difficulty has been shared by all students since 1891 (see Rappeport 1922, Conklin 1922). Hansemann counted in the hyperchromatic cells 18 to 40 chromosomes, while in the hypochromatic cells he found as few as seven.