Immunocytochemical localization of insulin- and somatostatin-like material in human breast tumors.

Four types of human breast lesions and C3H mouse mammary adenocarcinomas (type A) were examined for the immunocytochemical localization of cells containing hormone-like substances. Insulin- or somatostatin-like immunoreactive material was observed in scattered single cells and nests of tumor cells in seven of eight infiltrating duct carcinomas, and in the majority of tumor cells from an anaplastic carcinoma. A few somatostatin-immunoreactive cells were observed in only one of seven fibroadenomas studied. No immunoreactive cells were observed in mouse adenocarcinomas or in human breast dysplasias. These results suggest that cells with hormone-like immunoreactivity may be a common feature in two types of malignant human breast tumors.

Changes in uterine morphology which accompany the development of preneoplastic and neoplastic mammary lesions in old mice.

Because of the accumulating evidence that anatomical and physiological changes occur in sites and systems removed from primary tumors, uterine morphology during the development of mammary tumors in C3H/HeJ mice was investigated. C3H/HeJ mice contain the mouse mammary tumor (MTV) virus in their milk and have a high incidence of mammary tumorigenesis. The C3HeB/FeJ mice, used as one set of controls, do not contain the mouse MTV virus in their milk and have a low incidence of mammary tumorigenesis. In young cycling animals without mammary lesions, no differences in uterine morphology were detected between the two strains. However, there were striking differences between the uteri of animals with mammary lesions (C3H/HeJ mice) and the uteri of animals with no mammary lesions. The age-matched control uteri ( 3HeB /FeJ) contained involuted uterine glands and quiescent endometrial stromal and epithelial tissue. The C3H/HeJ mice with mammary tumors contained cystic uterine glands, a stimulated endometrium, and extremely variable endometrial epithelial cells with pleomorphic microvilli. The uterine endometrium from C3H/HeJ mice with preneoplastic lesions also had a stimulated appearance. Some of the uteri of mice with preneoplastic lesions contained cells with cilia or stereocilia. The altered uterine morphology was correlated with preneoplastic and neoplastic mammary lesions and was not related to age or strain differences.

Fine structure analysis and surface characteristics of mouse mammary gland adenocarcinomas.

Mammary adenocarcinomas from C3H/HeJ mice carrying the mammary tumor virus were studied by means of light, transmission, and scanning electron microscopy. The histological appearance of the tumors was variable; however, 60% were classified as type B adenocarcinomas, while 20% were type A and 20% were composed of equal regions characteristic of both types. Four populations of tumor cells were observed with the TEM. The most abundant of these, primitive glandular cells, were characterized by large, regular, euchromatic nuclei and cytoplasm containing numerous free ribosomes, little rough endoplasmic reticulum, few mitochondria, small Golgi complex and a variable number of type A virus particles. Specialized glandular cells contained highly pleomorphic nuclei, many lysosomes, lipid droplets, multivesicular bodies, profiles of rough endoplasmic reticulum and granules resembling secretory proteins. Myoepithelial cells and dark glandular cells with abundant organelles, large Golgi complexes, dense cytoplasmic matrix and very heterochromatic nuclei were observed infrequently. The SEM revealed tumor cells to be variable in size, shape and surface characteristics. Most cells were rough in texture, displaying irregular ridges, small blebs and a few short microvilli. The contours of some cells were smooth, and a few cells had short, irregular microvilli on limited regions of their surfaces. Cells lining ducts within the tumor had microvilli on their apical surface, but the number, size, shape and distribution of microvilli varied considerably. Cells lining ducts from non-tumor-bearing animals displayed less variation in size, shape and surface morphology.