Synchronous liver metastases of intracystic papillary carcinoma with invasion of the breast

A rare case of intracystic papillary carcinoma (IPC) with invasion had synchronous metastases to the liver at presentation. A 57-year-old postmenopausal woman noticed a right breast tumor 7 months prior to admission. Mammography showed an oval mass measuring 3.1 cm in diameter with no calcification, and ultrasonography showed an intracystic tumor with a papillary growth pattern. Fine-needle aspiration cytology revealed adenocarcinoma. Excisional biopsy revealed intracystic solid papillary carcinoma with invasion. The tumor was a clear-cell type with extracellular mucin. Two months after the initial biopsy, a screening ultrasonographic examination of the liver showed multiple hyperechoic masses. Abdominal contrast-enhanced CT scan and magnetic resonance imaging (MRI) showed multiple hypervascular masses compatible with metastatic tumors. No suspicious lesions were detected on examinations for malignancy in other organs. Distant metastases in cases of IPC with invasion are very rare. The potential of distant metastasis in IPC with invasion and the difficulty of evaluating invasive foci should be recognized. Careful evaluation of distant metastases is recommended.