Chorangiocarcinoma in a term placenta with postpartum pulmonary metastasis: a case report and review of the literature

Chorangiocarcinoma is an extremely rare primary placental neoplasm, with only five cases reported in the literature (Table 1). Some researchers considered it as a bona fide chorangiocarcinoma, but most cases described a chorangioma with abnormal trophoblastic proliferation. In spite of atypia in cytology, marked mitosis and tumor necrosis, chorangiocarcinoma was always reported benign. No metastasis or invasion has been described yet. Here, we report the first case of chorangiocarcinoma with postpartum pulmonary metastasis, combined with markedly elevated maternal βhCG level. Microscopically, the tumor is characterized by large caliber stem villus-like structures, composed of chorangioma in the stroma and surrounding malignant trophoblasts. These neoplastic trophoblasts are pleomorphic and represents striking necrosis, increased mitotic figures and high Ki-67 labeling index. Immunostaining shows these neoplastic trophoblasts are cytotrophoblasts and few intermediate trophoblasts. Overall, chorangiocarcinoma may be a chorangioma with variable trophoblastic proliferation, consisting of atypical trophoblastic hyperplasia, carcinoma in situ or even metastatic carcinoma.