What is the most likely diagnosis?
You are shown a CC view of the right breast following which a needle biopsy yielded fibroadenoma. A follow-up CC view of the right breast was obtained 6 months later.
A. Invasive lobular carcinoma B. Ductal carcinoma in situ C. Phyllodes tumor D. Tubular carcinoma
A. Incorrect. The most common presentations of invasive lobular carcinoma are a spiculated mass, an ill-defined or obscured mass and architectural distortion. Occasionally, lobular carcinomas are diffusely infiltrating and may show only subtle findings on mammography.
B. Incorrect. Ductal carcinoma in situ (DCIS) is usually detected on mammography with calcifications being the mammographic hallmark. The calcifications are typically fine, linear, discontinuous, and branching, often in a ductal distribution. In about 10% of cases, only a soft tissue mass can be seen on mammography.
C. Correct. Mammographically, most phyllodes tumors are large, circumscribed, noncalcified masses that are round, oval, or lobulated. When small, the appearance may be identical to a fibroadenoma. When large, the size may suggest the diagnosis. The most common clinical presentation is a large rapidly growing mass.
D. Incorrect. Tubular carcinomas are usually small, irregularly shaped, and have spiculated margins. They are typically slow growing and small at the time of diagnosis. Due to the small size and slow growth, most tubular carcinomas are detected on mammography rather than on palpation.