Metastatic Gestational Trophoblastic Neoplasia Leading to Acute Respiratory Failure and Death: A Case Report - About a Particularly Challenging Management in the Intensive Care Unit, and Exploring the Potential of Pembrolizumab in Treating Frail, Pretreated Gestational Trophoblastic Neoplasia.

Introduction: Gestational trophoblastic disease (GTD) includes rare tumors from abnormal fertilization, ranging from benign hydatidiform moles to malignant choriocarcinomas (CCs) and rare placental-site trophoblastic tumors. Management of GTD depends on FIGO scoring, with low-risk cases treated conservatively and high-risk or ultra-high-risk cases requiring multi-agent chemotherapy, often EMA-CO, with induction therapy recommended for patients at very high risk of early death. Case Presentation: We present the case of a 37-year-old female patient who developed an acute respiratory failure, requiring mechanical ventilation, 2 months after term delivery by cesarean section. The diagnosis of gestational trophoblastic neoplasia (GTN) was suspected due to high level of HCG in postpartum period and thoracic imaging suggesting multiple pulmonary metastases. No biopsy was available. She subsequently developed ventilator-associated pneumonia with severe acute respiratory distress syndrome (ARDS), requiring veno-venous extracorporeal membrane oxygenation support alongside concurrent polychemotherapy. After spending 61 days in the intensive care unit, and achieving biological complete remission based on HCG monitoring, the patient was transferred to the oncology ward. Due to prolonged hypoperfusion and hypoxemia, the patient developed ischemic cholangiopathy, severely constraining further therapeutic options. After 4 months of biological remission, the patient experienced a recurrence based on HCG rising and reappearing of pulmonary lesions on thoracic imaging in the lungs. In second line, the patient was treated with carboplatin, with no significant response. In third line, pembrolizumab was used, and the patient experienced a significant decrease in HCG. However, due to hematologic toxicity, we discontinued the treatment. Subsequently, the HCG level raised and the patient rapidly developed hemorrhagic cerebral metastasis and succumbed shortly thereafter. Conclusion: This case underscores the importance of prompt recognition and timely intervention in the management of patients with ARDS during the early postpartum period. GTN with lung involvement should be considered after excluding the other more frequent causes of ARDS. It also highlights how ECMO support enables the continuation of chemotherapy and the achievement of remission in CC. Furthermore, due to the inability to initiate the desired chemotherapy, immunotherapy was introduced as a possible treatment modality. Therefore, this case underscores the importance of adaptability in treatment plans based on patient-specific clinical conditions and collaborative decision-making with specialized centers. Finally, it emphasizes the efficacy of pembrolizumab, even as a monotherapy, in pretreated CC cases.