Pregnancy-like (pseudolactational) hyperplasia (PLH) is not a common lactational change in hyperplastic duct. PLH has been determined as an incidental finding in surgical breast biopsies for benign and malignant cases. Case reports Case 1A 45-year-old woman with a family history of breast cancer underwent a screening mammogram. According to the American College of Radiology Breast Imaging and Reporting Data Systems (BIRADS), suspicious microcalcifications (category IV) were detected in the upper quadrant of the left breast (Fig. 1). Ultrasound examination did not show any abnormality. Physical examination was normal. Stereotactic vacuum-assisted biopsy was achieved via 10-gauge Vacura on a prone mammography biopsy table (Fig. 2). Histopathologic examination showed pseudolactational hyperplasia including acini containing intraluminal calcification with a laminated appearance, hypersecretory cells with vesicular nuclei and vacuolated cytoplasm. Case 2A 75-year-old woman was admitted for screening mammogram. Mammograms showed retroareolar (Fig. 4). Physical examination was normal. She had been taking an antihypertensive drug including besarten and hydrochlorthiazide Ultrasound guided 14-gauge trucut biopsy was performed. Pathologic examination revealed hyperplastic secretory changes with pregnancy like changes including acinar cells with vacuolated eosinophilic cytoplasm and cystic hyperplasic ductus in multipl adenosis foci. localized microlobulated mass (BIRADS category IV) measuring 15 × 12 mm (Fig. 3). Ultrasound examination confirmed a hypoechoic mass in the same location JBR-BTR, 2013, 96: 25-26. PREGNANCY-LIKE (PSEUDOLACTATIONAL) HYPERPLASIA: UNCOMMON CAUSE OF MICROCALCIFICATIONS AND MASS IN TWO CASES