Placental metastasis from maternal carcinoma. A report of three cases.

Metastasis of a maternal neoplasm to the products of conception is extremely rare. Of the 54 reported cases in the world literature, only 14 (25%) showed fetal metastasis. More than 50% of the reported cases were not examined grossly or had no visually apparent tumor deposits. Malignant melanoma is the most common malignant maternal neoplasm to metastasize to the products of conception. We report three unusual maternal malignant neoplasms (one pancreatic and two breast cancer) with evidence of placental metastasis and discuss the risk factors for fetal involvement in these cases.