Clinicopathologic correlations and significance of clinically occult mammary lesions.

Experience with 189 clinically occult, i.e., nonpalpable breast lesions is presented. The described technique of localization and excision all but guarantees removal of even the smallest radiographically suspicious findings with an inconspicuous incision and minimal breast deformity. The incidence of carcinoma encountered in these 189 biopsies is 27.5%. Axillary node metastases were present in less than 25% of the invasive nonpalpable cancers, approximately half of what might have been expected if the lesions had been discovered in the usual manner. There were no patients with axillary node metastases among those with in situ ductal or microinvasive ductal carcinomas. This implies a better prognosis and lower death rate from breast cancer in these patients. Screening programs employing mammography, designed to detect breast cancers in this pre-palpable stage, are encountered as a means of uncovering a higher proportion of such cancers at an earlier stage in their natural histories.