What happened, in summary

A woman presented with a palpable breast mass. Imaging showed a large, solid or heterogeneous tumor with little blood flow and no suspicious axillary lymph nodes. The mass appeared dense on mammography without calcification and had a regular shape with a well-defined margin, an appearance that could resemble a less aggressive breast lesion.

She underwent mastectomy, and pathology confirmed adenoid cystic carcinoma of the breast. The tumor was classified as T3 after surgery. Adenoid cystic carcinoma is uncommon in the breast, but this patient’s larger tumor followed a more aggressive course. Bone and lung metastases were detected in the fourth year after surgery, marking recurrent metastatic disease.