[Management of ductal carcinoma in situ by the pathologist: current questions]

As a consequence of increased screening mammography, ductal carcinoma in situ represents a growing percentage of breast cancer diagnoses. The management of per-cutaneous biopsies as well as wire-localized surgical biopsies is a difficult task for pathologists. In this Article, we describe the diagnostic criteria of these lesions as well as the histopathological characteristics of their two principal differential diagnoses: atypical ductal hyperplasia and micro-infiltrating carcinoma. We also detail the utility of immunohistochemistry in the diagnosis of these lesions. This paper reviews the accepted prognostic factors for ductal carcinoma in situ and describes the important techniques needed to characterize them (grade and extent, status of margins and exclusion of microinvasion). Correct handling of pathological specimens, as detailed here, is one of the main keys for therapeutic success with ductal carcinomas in situ. Indeed, if dealt with adequately, such lesions should almost never affect the patient's long-term survival.