Pathology of preinvasive and excellent-prognosis breast cancer.

Recent advances in breast cancer treatment have made recognition of different prognostic groups mandatory. In addition, further experience with screening-detected lesions has resulted in definition of new associations. Therapeutic approaches to these frequently microscopic lesions are currently the source of much debate. This article reviews recent studies of excellent-prognosis carcinomas, as well as premalignant and other histologically defined lesions that indicate an increased risk for development or recurrence of carcinoma. Advances in fine-needle aspiration and in hormone receptor assays are also reviewed.