Synchronous, bilateral mastectomy

Sixty-four patients (mean age, 51 years) had mastectomies which were synchronous and bilateral. Sixty-one premastectomy biopsies (bilateral, 34 and unilateral, 27) demonstrated the following: invasive carcinoma, 17; noninvasive carcinoma, 24; combination of above, 10; and benign disease, 10. Twenty-two patients had bilateral mastectomy because of bilateral positive biopsy. Twenty-nine patients with unilateral carcinoma on biopsy had bilateral mastectomy. Thirteen patients had bilateral mastectomy despite benign disease only on biopsy (10) or no biopsy (3). Ten unexpected carcinomas (34%) were found in the contralateral breast in the 29 patients with carcinoma diagnosed on unilateral biopsy. The biopsy pathology of these 10 specimens was invasive ductal carcinoma in 1 and multifocal, noninvasive carcinoma (ductal, 3 and lobular, 6) in 9. An unexpected carcinoma may be found in the contralateral breast in a significant number of patients who are selected for bilateral mastectomy, particularly if the selection is on the basis of a noninvasive, lobular histology. Bilateral mastectomy may be appropriate for such patients, particularly when complicated by a strong family history and breasts which are difficult to assess by physical or mammographic examination.