Procedure: Ultrasound-guided Tru-Cut biopsy of the left breast mass, followed by left breast lumpectomy with complete excision.

Diagnosis: Benign fibroepithelial lesion suggestive of tubular adenoma.

Comment: The immunostain with the antibody anti-p63 and CK high molecular weight is diffusely positive.

Tubular adenoma (TA) of the breast, is a rare benign encapsulated tumor of the breast. It is closely related to the fibroadenoma of the breast and cannot be differentiated on imaging due to overlapping imaging features. Histologically, it is composed of densely packed ductal structures lined by epithelial and myoepithelial cells with scant connective tissue component, which helps in differentiating it from fibroadenoma.