Breast carcinoma is a dreaded disease. The incidence of breast cancer, which appears to be increasing, is 1 in 1500 women with an annual death rate of 4,000 from this disease in the United States (1). It is a cancer which threatens its victims with mutilation as weIl as early death. Although response to therapy has not been good, improved methods for earlier and more complete diagnosis are providing hope for better results. When a woman presents herself for routine breast examination, what diagnostic procedures are indicated? If a breast mass is present, what diagnostic and therapeutic methods are employed? When the mass proves to be malignant, what then? Should biopsy and mastectomy be a combined procedure? Should a positive biopsy be followed by a complete diagnostic work-up before definitive therapy is undertaken? While some answers may seem obvious and others less obvious, common medical practices vary considerably in response to all of these situations. No easy formula exists. Each patient must be given individual consideration and her* treatment carefully planned to incorporate all the diagnostic findings. Experience to date indicates that some diagnostic and therapeutic procedures have established efficacy while others are not very helpful and still others need more evaluation before their usefulness can be . assessed fully. Traditionally, treatment of breast cancer has been surgical. Through the years poor results from surgery, along with acquisition of knowledge of the lymphatic spread of this malignancy, prompted more and more extensive surgical procedures.