[Histological and ultrastructural analysis of infiltrative tumors of the human breast].

The ultrastructural analysis of the three main histological forms (adenocarcinoma, scirrhous carcinoma, and solid carcinoma) of infiltrative mammary gland carcinomas with regard to the histological grades of malignancy (I, II, III) has revealed that with the increase of the histological grade of malignancy the number of ultrastructurally differentiated cells decreased. No correlation between histological and ultrastructural findings has been found, however. In histologically highly differentiated adenocarcinomas of grade I of malignancy ultrastructurally nondifferentiated cells could mainly be found, but ultrastructurally differentiated cells predominated in a number of cases of histologically nondifferentiated scirrhous and solid carcinomas of grade III of malignancy. Some cases of histologically similar carcinomas showed predominance of ultrastructural differentiated cells, others of ultrastructurally nondifferentiated cells. These results should be taken into account in ultrastructural diagnosis and evaluation of prognostic significance of electron microscopic findings.