ABSTRACT
Purpose To explore the clinicopathological features, diagnosis, differential diagnosis and prognosis of placental mesenchymal dysplasia. Method The clinicopathological data of 5 cases with placental mesenchymal dysplasia were retrospectively analysed and related literatures were also re-viewed. Results All of 5 patients were consciously fetal movement disappeared or found abnormal ultrasound results at routine examination of the pregnancy. The placentas were enlarged, partly with oedematous "grape-like" cysts. On histologic exami-nation, enlarged villi with varying degrees of edema contained abnormal thick walled fetal blood vessels. The chorionic vessels were expanded and congested, and some chorionic villi showed mesenchymal cell hyperplasia. In immunohistochemical staining, p57 was positive, and Ki-67 showed low expression. There was no the trophoblastic proliferation. It's mainly differential diagnosis was hydatidiform mole.2 cases were accompanied with stillbirth. Conclusion The diagnosis of placental mesenchymal dysplasia can be confirmed by pathology examination. When a cystic placenta is detected by ultrasound examination, placental mesenchymal dysplasia should be considered in the differential diagnosis.