ICI-based therapy may improve overall survival in patients with primary pulmonary choriocarcinomaImmunotherapy may extend life for men with rare lung cancer

BackgroundPrimary pulmonary choriocarcinoma (PPC) is an exceptionally rare and highly aggressive extragonadal trophoblastic malignancy in males, with no established standard treatment. Cytotoxic chemotherapy alone generally yields limited therapeutic benefit, while the role of immune checkpoint inhibitors (ICIs) remains poorly defined.Case presentationHere, we report a 41-year-old man who presented with a six-month history of cough and was found to have a large right upper lobe pulmonary mass with multiple brain metastases. Histopathological examination revealed typical trophoblastic differentiation, and immunohistochemistry demonstrated diffuse positivity for HCG, CK7, GATA3, and SALL4, whereas TTF-1 and Napsin A were negative. Serum β-human chorionic gonadotropin (β-HCG) was markedly elevated (> 10, 000 mIU/mL), and no gonadal primary lesion was identified, confirming the diagnosis of primary pulmonary choriocarcinoma.Intervention/outcomeThe patient underwent multimodal treatment including radiotherapy, EMA/CO chemotherapy, EMA/EP combined with sintilimab, and third-line therapy consisting of nab-paclitaxel, bevacizumab, and penpulimab. Despite intensive treatment, the disease progressed rapidly with new intracranial and systemic metastases. Throughout the disease course, serial β-HCG measurements closely paralleled radiographic findings and provided timely guidance for therapeutic decision-making. In addition, we reviewed previously reported metastatic male PPC cases and performed an exploratory survival analysis, which suggested that patients receiving ICI-based therapy tended to have longer overall survival than those treated without immunotherapy.ConclusionAlthough these findings should be interpreted cautiously because of the limited sample size, this case highlights the highly aggressive nature of male PPC, emphasizes the diagnostic and monitoring value of dynamic β-HCG assessment, and supports further investigation of chemoimmunotherapy as a potential treatment strategy for this rare malignancy.