A Rare Case of Primary Pulmonary Choriocarcinoma Metastasizing to the Kidney: Diagnostic and Therapeutic Complexities.

BACKGROUND

Choriocarcinoma is a highly aggressive malignant tumor composed primarily of cytotrophoblast and syncytiotrophoblast cells without villi and is characterized by beta-human chorionic (beta-hCG) gonadotropin production. Although most cases are of gestational origin, rare non-gestational choriocarcinomas may arise from pluripotent germ cells in extragenital locations, independently of pregnancy. Primary pulmonary choriocarcinoma is extremely rare, and kidney metastasis has only exceptionally been reported in the literature.

CASE: We present the case of a 43-year-old patient with this unusual presentation. The diagnostic process began with a suspected implantation of unknown location and culminated in the final histopathological diagnosis based on lobectomy and nephrectomy specimens, including molecular genetic identification of the pulmonary tumor. Following thoracic and renal surgery, the patient received adjuvant chemotherapy and immunotherapy with anti-PD-1 monoclonal antibodies.

CONCLUSION

This case highlighted the diagnostic challenges posed by primary pulmonary choriocarcinoma with renal metastasis, an exceptionally rare clinical entity. Ongoing follow-up includes regular imaging studies and beta-hCG monitoring.