"Residual" mammary carcinoma following simulated partial mastectomy.

Treatment of mammary carcinoma by partial mastectomy rather than by total mastectomy and axillary dissection may diminish the chances of long-term cure by risking incomplete removal of all local carcinoma at the initial operation. This study was undertaken to determine by pathologic examination how often carcinoma might remain in the breast and axilla after partial mastectomy. The operation was simulated in 203 mastectomy specimens after operations for unilateral invasive carcinoma. In so far as could be determined on gross examination, the entire primary lesion was included in the quadrant which was excised in the simulated procedure. Among 100 women with primary lesions less than 2 cm in diameter, 26% had carcinoma in the breast which remained after simulated partial mastectomy. Six percent of them also had axillary node metastases. An additional 30% only had axillary node metastases. When the primary lesion was more than 2 cm in diameter, 38% of patients had carcinoma in the breast after simulated partial mastectomy, of whom 29% also had axillary metastases. After simulated partial mastectomy, carcinoma was found in 80% of breasts from patients with lesions in the subareolar area, in contrast with 25-35% of patients with a primary carcinoma in one of the four quadrants. None of the 9 patients with medullary and colloid carcinomas that measured under 2 cm had axillary metastases or carcinoma in the breast outside of the primary quadrant. The findings suggested that a familial history of breast carcinoma or a large primary lesion may be associated more often with multifocal disease, but factors such as age at diagnosis, axillary status, and the mammogram report did not have significant predictive value for distinguishing between patients who did or did not have carcinoma in breast tissue after the primary had been removed by a simulated partial mastectomy.