A Case Report on Ductal Carcinoma in situ Arising from Axillary Accessory Breast Tissue.

Accessory breast tissue can appear along the mammary ridge, extending from the axilla to the groin, with the axilla being the most common site. Malignancies arising in accessory breast tissue are rare, representing approximately 0.3%-0.6% of all breast cancer cases. When evaluating accessory breasts, it is essential to apply the same management strategies used for conventionally positioned breasts. This report presents a case of ductal carcinoma in situ originating from accessory breast tissue in the axilla of a 55-year-old woman. The diagnosis was established through a comprehensive assessment involving mammography, ultrasound, and magnetic resonance imaging. Since the axillary accessory breast tissue wasn't initially included in the routine mammography, we added an axillary tail view to evaluate the extent and morphology of malignant microcalcifications.