Changing concepts in establishing the diagnosis of breast masses.

Experience with 297 consecutive biopsies of breast masses for 235 benign lesions and 62 carcinomas over a thirty month period has been reviewed. The correct preoperative clinical diagnosis was made in 91% of cases. Of patients with carcinoma, 66% were suspected clinically, and 88% of those clinically suspected were confirmed by needle biopsy alone. The mammographic diagnosis was correct in 89% of cases with 6% false-negatives. The clinical and mammographic diagnosis differed in 27 patients, with the clinical diagnosis being correct in 85%. No patient thought to have cancer on both clinical and mammographic grounds had a benign lesion. These data indicate that the approach to establishing a tissue diagnosis in women with breast masses can be simple and inexpensive. Local anesthesia can almost always be employed, and the diagnosis of breast cancer can usually be confirmed with certainty by needle biopsy alone.