[Intra-Cystic Mucinous Carcinoma of the Breast - A Case Report].

A 75-year-old woman consulted our hospital for a lump on her left breast. The tumor was 5 cm in diameter and was palpable in the ABE area. The tumor was identified as an intra-cystic tumor using ultrasonography. Contrast-enhanced magnetic resonance imaging showed a tumor with cystic components that were slowly stained in a dynamic study. A fine needle aspiration biopsywas performed, and the pathological diagnosis was class V. Metastatic work-up revealed no evidence of metastasis. Therefore, we determined the clinical stage as T3N0M0, stage II B. Breast reduction surgeryand sentinel lymph node biopsywere performed on the left breast. The histopathological findings from the surgicallyresected specimens showed mucinous components with some invasive ductal components. Therefore, the pathological diagnosis was mixed mucinous carcinoma of the breast. The tumor size was 8 cm in diameter. Here, we report a case of mucinous carcinoma that showed a huge intra-cystic tumor, which is rarely described in the literature.