When a Differential Diagnosis Is Fundamental: Choriocarcinoma Mimicking Lung Carcinoma.

Background: Choriocarcinoma is a rare malignant disease that is usually associated with a gestational event. Lung metastasis with no evident primary origin and choriocarcinoma, which mimics features of non-small-cell lung cancer, might be misdiagnosed as adenocarcinoma or large-cell carcinoma. This is a pivotal clinical concern since the tumor can lead to various symptoms, seriously affecting the quality of life and can escalate rapidly, with a high mortality rate, compared to lung cancer. Methods: We reported a case of a 37-year-old woman with a history of one-year enhancement of beta-human chorionic gonadotropin levels and only a single nodule in the right upper lobe, with no abnormal findings on the gynecological investigation. Then we retrospectively examined all cases treated in the Division of Thoracic Surgery at the European Institute of Oncology in the last twenty years (from 1998 to 2018). Results: This was the first time in our experience that choriocarcinoma presentation was with a single nodule without a gynecological finding. Moreover, the differential diagnosis between lung carcinoma and choriocarcinoma was achieved only after surgical removal. Conclusions: As confirmed by our literature search, precise and expedited differential diagnosis is essential in choriocarcinoma care (both with single or multiple metastases), to successfully remove the tumor and increase the patient's chances of survival.