Incidental Findings in Reduction Mammoplasty Specimens in Patients with No Prior History of Breast Cancer. An Analysis of 783 Specimens.

Breast reduction surgery is a common procedure and the rate of incidental findings in the removed specimens varies between 0% and 4.6%. There are no guidelines about pathological evaluation of breast reduction surgery. We reviewed all pathology reports of patients undergoing breast reduction surgery in a single tertiary institution in Brazil from January 2008 to August 2014. Exclusion criteria were a personal history of breast cancer, unclear reason for mastectomy and incomplete data on the pathology report. We considered "relevant findings" flat epithelial atypia, atypical hyperplasia, carcinomas in situ and invasive carcinoma. Of 1672 specimens from breast reduction surgery, 783 met inclusion criteria. Median patient age was 40 (8-77), 91% underwent bilateral mastectomy and 57% of the specimens weighted less than 200 g. In 55% of cases, 4 or more paraffin blocks were sampled. There were 40 (5.1%) relevant findings and the most common was atypical lobular hyperplasia (16-2%). There were 3 invasive carcinomas (0.38%). In multivariate analysis, the only variables associated with a higher odds of relevant pathological findings were patient age ≥ 40 (OR 4.73 CI95% 1.98-11.3 p < 0.001) and sampling of ≥4 paraffin blocks from each specimen (OR 6.69 95% CI 2.25-19.9 p < 0.001). The incidence of pre-malignant and malignant lesions in specimens from breast reduction surgery is around 5%, but this risk is significantly higher for patients older than 40 years-old. Sampling at least 4 paraffin blocks from each specimen significantly increases detection rates.