Congenital unilateral athelia associated with mammary Paget's disease, high-grade ductal carcinoma

Background: Congenital unilateral athelia is an extremely rare breast malformation, most commonly associated with ectodermal dysplasia or systemic congenital syndromes. Isolated congenital athelia without concurrent malformations is even rarer, and its long-term neoplastic risk remains poorly characterized. Case description: We report a 57-year-old postmenopausal woman with congenital isolated right athelia who presented with a 2-year history of bilateral breast masses. Multimodal imaging revealed multifocal lesions in the right breast, and postoperative pathology confirmed synchronous mammary Paget's disease, extensive high-grade comedo-type ductal carcinoma Key findings: This is the first reported case of isolated congenital athelia complicated with triple synchronous epithelial breast malignancies. Congenital nipple absence introduces substantial challenges to preoperative imaging localization, intraoperative margin assessment, and postoperative surveillance. Ultrasonography, with flexible scanning planes and real-time performance, shows unique advantages in disease management for such conditions. Conclusion: Although no causal relationship is established between congenital athelia and breast carcinogenesis, careful clinical and imaging evaluation is mandatory for patients with congenital nipple-areolar abnormalities. Rational application of multimodal imaging is critical for early diagnosis and long-term surveillance in this rare population.