Elektronenmikroskopische Untersuchungen an der Tumor-Bindegewebsgrenze beim Mammacarcinom der Frau

Intramitochondrial rod-like inclusions in human breast tumors

Ultrastructural screening of human breast tumor biopsies has revealed, in 43% of the carcinomas, and in 16% of the benign lesions examined. the presence of rod-like inclusions in mitochondria of epithelial cells. The inclusions are cylindrical in cross section, with a diameter of about 50 nm, and show regular striations in longitudinal sections. They are probably derived from cristae. Mitochondria with inclusions are usually enlarged and are found most frequently in epithelial cells of invasive tumors and near zones of tumor necrosis. Similar although not identical inclusions have been observed by other investigators in the liver of women with hydatidiform mole or choriocarcinoma, of pregnant women, and of women taking oral contraceptives. Identical inclusions have been found in mitochondria of HeLa cells treated with anti-HeLa serum. Although no clear-cut correlations were found between the finding of inclusions and parameters such as age of patients, nuclear grade or lymphocytic infiltration of the breast tumors, it is conceivable that the presence of mitochondrial inclusions reflects the effect of hormonal or of immunological factors.

On the histology of human seminoma: development of the solid tumor from intratubular seminoma cells

Intratubular seminomas of the testis associated with solid tumors were studied by light and electron microscopy in order to obtain information about the earliest stage of emigration from the tubules and invasion of the interstitial space. Careful examination of numerous sections reveals that at this stage neoplastic cells protrude into evaginations of the tubule covered by basement membrance or directly invade that membrane. At the site of tumor cell emigration, the basement membrane is thickened and multilayered. Tumor cells devoid of basement membrane were found in the interstitium. Their transmigration through the basement membrane was never observed. Subsequent to the migration of seminoma cells the tubules are smaller in diameter and contain only Sertoli cells. From the observations described it is inferred that tumor cells in the interstitial tissue increase in number, form strands and lobules, and finally build up the solid tumor.

[The ultrastructure of mixed mammary gland tumors in bitches. IV. The incidence of myoepithelial cells in formation of spindle cells (author's transl)]

Spindle cells of myomatous formations of 19 canine mixed mammary tumors were studied by light and electron microscopy. The EM findings indicate that the spindle-shaped tumor cells are mostly of myoepithelial origin. However there were also formations of spindle cells which consisted of fibroblasts or fibrocytes. By light microscopy they are not always clearly distinguishable.