Congenital soft tissue sarcoma of the neck with placental metastasis: a case report

Abstract Congenital round cell soft tissue sarcoma with metastasis to the placenta is rarely described. We report a case of a large soft tissue sarcoma of the left neck from a female fetus delivered at 36 weeks and 3 days with metastasis to the stem villous vessels of the placenta. The tumor showed mixed features of Ewing sarcoma/primitive neuroectodermal tumor (PNET) and infantile fibrosarcoma with ETV6 :: NTRK3 fusion gene transcript. The clinical significance and diagnostic pitfalls are discussed.