ABSTRACT
The histological reporting of breast cancer has evolved with the introduction of minimum datasets and synoptic reports, refl ecting increased knowledge of the disease and the sophistication of surgical and oncological management. These developments ensure that relevant information needed by clinicians to inform the patient of their prognosis and determine the optimum clinical management is clearly and concisely presented (3,4). These essential data include information on invasive cancer size, grade, and type, the presence and extent of an in situ component, the presence of lymphovascular space invasion, proximity to margins, and hormone receptor and HER2 status. This chapter focuses on the different histological subtypes of breast cancer, their clinical signifi cance, and where relevant cognate molecular characteristics. Other prognostic factors are discussed in more detail in chapter 26, and the molecular biology of breast cancer is discussed in greater depth in chapter 29.
