Abstract
RATIONALE: The clinical symptoms and signs of lung cancer patients during pregnancy are not specific, making early clinical diagnosis difficult. The unique physiological and pathological changes in pregnant women significantly increase the risk of pulmonary embolism during pregnancy, but its diagnosis is more challenging compared to nonpregnant patients. PATIENT CONCERNS: This article reports a case of a pregnant woman with lung cancer misdiagnosed as pulmonary embolism, ultimately leading to severe conditions requiring extracorporeal membrane oxygenation (ECMO) treatment. During ECMO support, the patient developed spontaneous intrauterine fetal death and natural expulsion. DIAGNOSES: The final pathological diagnosis is lung adenocarcinoma. INTERVENTIONS: After admission, the patient received ECMO support, anti-infection, anticoagulation, blood transfusion, liver protection, and nutritional support. During the fetal expulsion period, blood transfusion was administered to improve coagulation, and medications were actively used along with the placement of an intrauterine balloon to promote uterine contraction and hemostasis. After a diagnosis of lung cancer, targeted therapy with alectinib was administered. OUTCOMES: The patient avoided postpartum hemorrhage, safely passed the critical period, and the antitumor treatment for lung cancer was effective, leading to a favorable prognosis. LESSONS: This case reminds us that pregnant patients with recurrent respiratory symptoms should undergo necessary imaging examinations promptly to avoid misdiagnosis. Pregnant patients receiving ECMO therapy are at risk of sudden fetal death and spontaneous fetal expulsion, with a significantly increased risk of severe hemorrhage during the expulsion period. It is crucial to detect and prevent hemorrhage in a timely manner during the expulsion period to avoid serious complications.