A rare case of extensive ductal carcinoma in situ of the breast with secretory features

We report a very rare case of extensive ductal carcinoma in situ (DCIS) of the breast with secretory features in a 30-year old Japanese woman. The patient presented with a nodule in the lower inner quadrant of the left breast measuring approximately 2–3 cm, accompanied by an irregular tumor shadow with segmental microcalcification on mammography. These findings suggested malignancy, and excisional biopsy was performed following core needle biopsy. Pathological diagnosis was that of DCIS with secretory features. A treatment plan of simple mastectomy and sentinel lymph node biopsy was chosen. Most previous reports have only described invasive secretory carcinoma of the breast. We have only been able to find 2 case reports of non-invasive secretory lesion in the English literature to date. Because the characteristics of this lesion are not widely known, we thought it important to share our findings.