[Diseases of the female breast: clinical pathology]

Histopathology and cytopathology are important for diagnosis and treatment planning in diseases of the breast today. Standardized criteria must be used in diagnosis of fibrocystic disease to define the cancer risk. Atypical hyperplasia (ductal or lobular) and lobular carcinoma in situ (marker of increased cancer risk) do not alone justify aggressive surgical treatment. Ductal carcinoma in situ is a pre-cancer and can be treated by breast-conserving surgery. Risk of progression in node-negative breast cancer is defined by histopathologic standard criteria. Today it is not yet decided which of the many biologic parameters should be used for risk definition.