Ultrasound features and clinicopathologic correlations of breast adenoid cystic carcinoma: a retrospective observational study.

Background: Adenoid cystic carcinoma of the breast (ACCB) is a rare form of triple-negative breast cancer characterized by generally indolent but variable clinical behavior. Despite distinct pathological and molecular features, its ultrasound characteristics remain poorly defined. This study aimed to describe the sonographic and clinicopathologic features of ACCB. Methods: This retrospective study reviewed histologically confirmed cases of ACCB diagnosed at a tertiary medical center between June 2015 and June 2025. Demographic, clinical, ultrasound, and pathological data, including Results: Twelve patients (11 women, 1 man; median age 60.5 years) were identified. Most lesions showed malignant ultrasound features, most commonly irregular shape (11/12) and hypoechogenicity (12/12); indistinct margins were observed in seven cases. Calcifications were present in ten lesions, and posterior acoustic shadowing in two. All lesions were categorized as Breast Imaging Reporting and Data System (BI-RADS) categories 4-5. Histologic subtypes included classic [6], solid-basaloid [5], and mixed [1]; Conclusions: ACCB generally exhibits malignant ultrasound features and is typically categorized as BI-RADS 4-5, but lacks disease-specific imaging characteristics. Histopathologic and molecular confirmation, particularly