The diagnostic and therapeutic challenges of pulmonary epithelioid trophoblastic tumor: A case report and literature review.

[RATIONALE] Primary pulmonary epithelioid trophoblastic tumor (ETT) without a uterine primary is exceptionally rare, with merely 29 cases documented in the English-language literature. Therefore, a standardized management protocol has yet to be established, and the optimal treatment strategy remains poorly defined.

[PATIENT CONCERNS] A 31-year-old woman presented to a local hospital with irregular vaginal bleeding and was initially diagnosed with an ectopic pregnancy due to elevated serum beta-human chorionic gonadotropin (β-hCG) levels. Following treatment with diagnostic curettage and methotrexate, her β-hCG levels plateaued. The patient was subsequently referred to our institution for further investigation. Imaging revealed a 1.7 cm × 1.5 cm pulmonary nodule, which was initially suspected to be peripheral lung cancer.

[DIAGNOSES] Video-assisted thoracoscopic resection and subsequent histopathological analysis confirmed the diagnosis of ETT.

[INTERVENTIONS] The patient received 4 cycles of combined EMA/EP (etoposide, methotrexate, actinomycin D/etoposide, cisplatin) chemotherapy after the surgery.

[OUTCOMES] During 3 years of follow-up, her menstrual cycles were normal and there was no evidence of disease recurrence.

[LESSONS] This case highlights the diagnostic challenges and management strategies for pulmonary ETT, particularly in preserving fertility while ensuring optimal oncological outcomes.