Breast Sclerosing Adenosis and Accompanying Malignancies

Sclerosing adenosis (SA) is a less common histopathological lesion of the breast that can coexist with proliferative lesions as well as malignancies. We aimed to analyze the clinicopathological characteristics of SA and to investigate the radiological features of SA.Patients who underwent breast surgery at our institute from 2007 to 2013 were retrospectively reviewed. A total of 815 breasts (722 patients) were included in the final analysis. Synchronous bilateral SA was defined as the detection of another SA arising in the contralateral breast within 1 month after surgery for the initial breast lesion. Baseline characteristics, imaging records (ultrasonography, mammography, and magnetic resonance imaging [MRI]), and pathology were included in the analysis.The median age at diagnosis was 47 years old. The majority of patients had unilateral non-Bc-SA (457/722). Among 102 patients with bilateral SA, 78.4% were diagnosed synchronously. In total, 26 patients suffered from synchronous bilateral breast cancer. Upon final pathological investigation, 226 cases were SA involving breast cancer (Bc-SA), most (56.2%) of which were ductal carcinoma in situ (DCIS). In addition, lobular carcinoma in situ (LCIS) and diseases that involved LCIS also comprised up to 11.1% of cases. The majority of SA cases (405; 49.7%) had no obvious symptoms except for imaging changes in mammography or ultrasound. Compared with non-Bc-SA cases, Bc-SA cases were more likely to exhibit features of mass (32.8% vs. 28.6%) and architectural distortion (20.4% vs. 13.0%) on mammography. Ultrasonography, mammography, and MRI revealed unsatisfactory sensitivity and specificity to differentiate Bc-SA from non-Bc-SA. MRI exhibited the highest sensitivity and lowest specificity, whereas the specificity of mammography was as low as 50.0%.A tendency for synchronous bilaterality in both Bc-SA and non-Bc-SA was noted. DCIS was the most commonly observed malignancy involved in Bc-SA. Although most patients with SA were asymptomatic, the ability of imaging studies to accurately differentiate non-Bc-SA from Bc-SA remained unsatisfactory.