Abstract: | Ultrastructural analysis of mammary carcinoma (45 cases) and its metastasis in the lymph nodes (21 cases) revealed the tissue specific features of the mammary gland: big ducts and intercellular canaliculi, microvilli, various specialized cell-to-cell contacts, basal membrane. Tissue specific features are not associated with a certain organ. In mammary carcinoma, they are more pronounced in carcinomas in situ, invasive tumours of the 1st grade of malignancy (adenocarcinoma) and specific histologic variants. They are less pronounced in solid and scirrhous invasive tumours of the 2nd and especially 3rd grade of malignancy. However it is impossible to conclude about the anaplasia degree on the basis of the number of and the correlation between various tissue specific features. Metastasis retains the capacity of cancer cells to form the tissue specific ultrastructural elements. The tissue specific properties of mammary carcinoma determine the diagnosis in cases when the question on the tissue origin of the tumour is to be solved. |