Ultrastructural Study of the Nuclei of Normal, Dysplastic, and Carcinomatous Epithelial Cells of the Human Cervix Uteri

Abstract

The nuclei of epithelial cells of the uterine cervix of normal women and of patients with various degrees of dysplasia, carcinoma in situ, and invasive carcinoma were studied by means of electron microscopy. Nuclear ribonucleoprotein components and chromatin were contrasted using preferential methods for RNA and DNA. Changes in the distribution of the extranucleolar ribonucleoprotein-containing structures were found, ranging from low-grade dysplastic lesions to invasive carcinoma. Compared with normal epithelial cells, dysplastic and neoplastic cells possess more nuclear bodies, as well as deep invaginations of the nuclear envelope and lobulations. Morphometric parameters estimated were nuclear volume, numerical density of perichromatin granules (PCG), and fraction of nuclear volume occupied by compact chromatin. The pattern of values of these parameters in the cell layers of normal cervical epithelium was disrupted in all the lesions. These data suggest that the processes studied induce early alterations in transcription and processing and/or exportation of mRNA to the cytoplasm. Two populations of cells were found in invasive carcinomas, one with large nuclei, sparse compact chromatin, and few PCG, and the other with small nuclei, abundant compact chromatin, and numerous PCG. Their morphologic features indicate that the former population is composed of relatively undifferentiated cells, while the letter is made up of well-differentiated cells which could be neoplastic or entrapped normal cells.

Morphometric differentiation of squamous cell carcinoma and adenocarcinoma of the cervix

“…In the nucleus there occurs one or more prominent nucleoli. There are changes in the size and shape of the nucleus, as well as changes to its structure [1]. Morphometry of cells found in cervical smears allows one to assess the size and diameter of cells and their nuclei.…”

“…Cervical cancer is one of the most common cancers found in women [1,2] and accounts for about 12% of these tumors. Each year there are about 500 thousand new cases of cervical cancer among women.…”