Recent progress in the histological typing of human breast tumours

Recently, new concepts in the histological typing of human mammary carcinomas have been proposed. The basic subdivision into the two major categories, i.e. ductal and lobular carcinomas, remains valid. In so far as lobular carcinomas are concerned, histological variants have been recognized: invasive carcinoma without an in situ component as well as solid and signet-ring cell forms. Special types of duct carcinoma have been defined with more accuracy, those deserving special attention being, scirrhous, tubular and secretory forms. The validity of the diagnosis of so-called apocrine carcinoma is discussed, as is the place of mucus-secreting tumours in the histologic classification.