Complex breast masses may appear as suspicious ultrasound findings that usually warrant biopsy. Ductal Cell Carcinoma In-Situ (DCIS) is a form of breast cancer with a non-uniform appearance and malignant potential. A longitudinal review of mammary gland ultrasound (with high frequency transducer) within a three-year period was conducted. Differential diagnosis of fibroadenoma, lactating adenoma, mastitis, galactocele, breast cancer, abscess and "general" masses greater than 16 mm in diameter was stratified. Based on the Breast Imaging Reporting in Data System (BIRADS), lesions were classified as benign or malignant and recommendations of cytology made in cases of observed overlap findings. Image sonomorphologic information on mass-echogenic halo and non-uniform orientation were documented; while malignant factors like scar tissue, focal fibrosis and papillomas may be associated with a false positive (conclusion) result. Doppler studies on further mass evaluation is encouraged.