[Infraclinical breast lesions: apropos of a retrospective study of 261 cases]

To determinate the rate of malignant lesions discovered after surgery for nonpalpable breast lesions diagnosed by radiology.

We performed a retrospective study of 261 patients who underwent surgery for nonpalpable breast lesions at the Saint-Etienne University Hospital between 1991 and 1998. We included women who did not have any palpable breast lesion. We excluded bilateral lesions and nonpalpable lesions associated with a palpable lesion in the same breast. We grouped outcome by alarming signs, those of complementary exams such as mammography, ultrasound, fine-needle aspiration biopsy and setreotaxis core needle breast biopsy in their sensitivity, specificity and predictive values, and classed results by pathology and type of surgery performed. All nonpalpable lesions were localized by stereotaxis maneuvers.

In our series, 61.7% of the patients were seen for individual detection, 3% had participated in mass screening programs and 35.3% were referred for suspected conditions. The predictive value of malignant lesions on mammography, analyzed in all cases and interpreted in 275, was 42.2%. The sensitivity and specificity of ultrasound exams performed in 50.2% of the cases were 85% and 91% respectively. Fine-needle aspiration biopsy and core needle biopsy were performed in 45 (18%) and 23 (9%) cases respectively. Twelve patients underwent total mastectomy with axillary dissections, 58 had tumorectomy with axillary dissections, and 191 had simple tumorectomy. Benign lesions were found in 128 (49.1%) cases, atypical hyperplasia in 10.7%, carcinoma in situ in 57 (cases 21.8%). The rate of malignant lesions was 38.6%. I was 50.9% when borderline lesions (atypical hyperplasia and in situ lobular carcinoma) were included.

In our series, 38.6% of all nonpalpable operated breast lesions were cancers. Ultrasound, fine-needle aspiration and needle core biopsy showed high sensitivity and specificity allowing good biopsy outcome.