Fatal massive pulmonary thromboembolism and concomitant pulmonary trophoblastic embolism associated with exaggerated placental site reaction: a case study

Pulmonary embolism is a major cause of maternal morbidity during pregnancy. Beside the frequently encountered thromboembolism, trophoblastic cell embolism has also been reported in a few case reports. This phenomenon may be symptomless in physiological gestational process but is more pronounced in contexts of preeclampsia or gestational trophoblastic disease. It was exceptionally reported to be associated with death. Here, we report the case of a 15-year-old girl, who experienced dyspnea followed by cardiac arrests and disseminated intravascular coagulation. Echocardiography showed a massive proximal pulmonary embolism. Abdominal sonography revealed that she was 11 weeks pregnant. Autopsy confirmed the presence of multiple clot emboli in the proximal pulmonary arteries. Additionally, the histopathological examination showed a massive syncytiotrophoblastic embolism in the lung microcirculation. Microscopic examination of the uterus revealed an exaggerated placental site reaction. In conclusion, this exhaustive post-mortem study describes a previously unreported association between exaggerated placental site reaction and pulmonary trophoblastic embolism, with fatal issue. Forensic pathologists should be aware that a large sampling of the lungs and uterus and examination of both placenta and fetus are needed to achieve this diagnosis. This case study emphasizes the need for further work elucidating pathways of trophoblast deportation.