Synchronous Bilateral Solid Papillary Carcinomas of the Breast

We herein report a case of synchronous bilateral solid papillary carcinoma of the breast. A 73-year-old female had a mass that was detected in the right breast on mammography. An ultrasound examination revealed one intracystic tumor in the right breast and two tumors in the left breast. A fine-needle aspiration biopsy of these three tumors was performed, which revealed a diagnosis of malignancy. A magnetic resonance imaging examination of the breasts showed diffuse small nodules surrounding these tumors bilaterally. Bilateral partial mastectomy and a sentinel lymph node biopsy were performed. Lymph node metastasis was detected in the right axilla, and additional lymph node dissection was performed. The pathological diagnosis was synchronous bilateral breast cancer, invasive ductal carcinoma NOS of the right breast, mucinous carcinomas of the left breast, and bilateral SPCs. A wide range of surgical margins were positive for SPCs, and additional bilateral total mastectomy was then performed. To the best of our knowledge, little is known about synchronous bilateral SPCs. Our case indicates that some SPCs can be widely scattered and make up a variety of invasive carcinomas. It is difficult to make a correct preoperative evaluation in such cases. 1. Introduction Solid papillary carcinoma (SPC)　is a special type of carcinoma that accounts for 1.1–1.7% of all cases of breast cancer [1–5]. It is a malignancy with low-grade nuclear atypia that develops predominantly in elderly patients and clinically behaves as a mass-forming in situ carcinoma. SPC is also known to infrequently involve some types of invasive ductal carcinoma, especially mucinous carcinoma. We herein report a case of synchronous bilateral solid papillary carcinoma of the breast. 2. Case Report A 73-year-old female presented with a mass in the upper inner quadrant of the right breast. Anamnesis and the patient’s family history were not appreciable. The tumor was mobile without evidence of dermal invasion, and the axillary lymph nodes were impalpable. A round, high-density mass measuring 17？mm in diameter (tumor 1) was found in the right breast on a mammogram (Figure 1(a)). An ultrasound examination revealed one intracystic tumor in the right breast (Figure 1(b)) and two tumors (each 8？mm in diameter) in the left breast (Figures 1(c) and 1(d), resp.). A magnetic resonance imaging examination also showed these tumors (Figures 1(e), 1(f), and 1(g), resp.) with diffuse small nodules surrounding the tumors in the bilateral breasts (Figures 1(h), 1(i)). The serum CEA and CA15-3 levels were not