Breast carcinoma with choriocarcinomatous features: a case report and review of the literature

BACKGROUND: Breast carcinoma with choriocarcinomatous features (BCCF) is a rare variant of breast cancer, characterized by high expression of human chorionic gonadotropin (HCG) in cancer cells such as multinucleated syncytiotrophoblast-like giant cells. The first case of BCCF was reported in 1981 by Saigo and Rosen. Only one case of BCCF was reported to show no component of breast ductal carcinoma, and only partially cancer cells, such as multinucleated syncytiotrophoblast-like giant cells, expressed HCG in all previous BCCF cases. Here, we report the first BCCF case without any component of breast ductal carcinoma in which HCG was found to express in all cancer cells. CASE PRESENTATION: A 32-year-old female patient presented with a small lump in her left breast 3 years prior. The mass was clinically suspected to be breast infiltrating ductal carcinoma based on breast excisional biopsy and magnetic resonance imaging findings. Due to rupture and bleeding of the left kidney, the left kidney excisional biopsy was performed. After a retrospective analysis of the initial excised breast cancer and breast cancer metastatic to the kidney, the cancer cells were positive for HCG by immunohistochemistry, and multinucleated or mononucleated giant cells resembled syncytiotrophoblastic and cytotrophoblastic cells which could be seen in a background of poor differentiated breast carcinoma and extensive necrosis and hemorrhage in the lesion. Thus, a final diagnosis of BCCF and BCCF metastatic to the kidney was made. After combination of surgical resection (the affected left breast and left kidney wereremoved) and consecutive chemotherapy consisting of docetaxel, epirubicin, cisplatin, lobaplatin, and capecitabine, the patient achieved favorable therapeutic efficacy (the HCG level returned to normal values, the metastatic lesions in the lungs disappeared, and the survival was 37 months). Capecitabine was very efficient and highly recommended due to its superior efficacy in reducing the HCG level and eliminating the metastatic lesions in the lungs. CONCLUSIONS: This is the first report of a rare case of BCCF without any component of breast ductal carcinoma, featured by high expression of HCG in all cancer cells. Combination of surgery and chemotherapy (especially capecitabine) achieved a favorable therapeutic efficacy.