[Multicentric carcinoma and atypical hyperplasia of the mammary gland (author's transl)].

A study for multiple primary cancer in the female mammary gland was performed. In 145 cases of mammary cancer, blocks for histological analysis were taken in a special system following routine examination of the specimen. Three sagital sections each of one inch width were taken from the outer, medium and inner region and from each of these 6 small blocks were cut. By this constant pattern of histological screening, 9 cases out of 145 were found showing multiple primary cancers. Among these Carcinoma solidum scirrhosum was the most frequent tumor type. This percentage of 6.2 is considerably lower than that given in the pertinent literature. Residual cancer following biopsy was found in 81% of the 145 cases, although extensive excision had been tried by the first operation. The entity of atypical epithelial hyperplasia which has to be differentiated from Carcinoma in situ was observed in 40.5% including ductal and ductular system.