RESUMEN
Primary mucinous cystadenocarcinoma (MCA) of the breast is a rare variant of breast carcinoma. A 68-year-old female patient presented to the general surgery clinic with pain and swelling in the right breast. A mass was detected in the upper outer quadrant, and a fine-needle aspiration biopsy was performed. The May-Grünwald Giemsa stained slides showed aggregates of mucin-rich pleomorphic cells with large nuclei in a mucinous background containing discohesive single cells. The Papanicolaou stain revealed a papillary structure composed of malignant epithelial cells in a necrotic background. A modified radical mastectomy was performed, and upon gross examination, two tumors were discovered in the central and upper outer quadrants. The first tumor, located centrally, was identified as invasive lobular breast carcinoma. The second tumor was an MCA with cytokeratin 7(+) and cytokeratin 20(-), and was determined to be the primary MCA of the breast based on clinical and radiological information. Immunohistochemistry revealed that the tumor cells were negative for estrogen receptor and progesterone receptor, and HER2 was 2+. Fluorescence in situ hybridization analysis detected HER2 gene amplification. During the 72-month follow-up, there were no findings compatible with recurrence or new metastasis. Although primary MCA is rare, it causes differential diagnosis problems and has different biological behaviors.
RESUMEN
Metaplastic breast carcinoma (MBC) is a general term defining a heterogeneous group that includes biphasic lesions, with both malignant epithelial and mesenchymal tissue components. Although its clinical findings are similar to those present in invasive ductal carcinoma, it rarely presents with the findings of inflammatory breast cancer. It is generally seen in the fifth decade. MBC spreads via lymph and blood circulation. Most common distant metastasis areas include lungs and the bone. Although the treatment generally relies on the same principles applied in invasive ductal carcinoma, a more aggressive treatment should be employed in at-risk groups due to higher rates of local recurrence. In this study, we aimed to discuss clinicopathological features and treatment approach in 5 women with MBC.