Malignancy occurs in approximately 1 in 1,000 to 1,500 pregnancies. Metastatic involvement of the placenta is rare and the exact incidence is unknown.
Placental metastases are usually of maternal origin and occur at an advanced stage of the disease. In this article, we describe a case of recurrent breast cancer that metastasized to the placenta.
Personal history and immunohistochemical examination of the placenta played a key role in the diagnosis.