Supplementary Material for: Remarkable Response to Cisplatin-Based Chemotherapy and Long-Term Remission in a Young Male with Widespread Extragonadal Choriocarcinoma: A Case Report and Literature Review

Introduction
Choriocarcinoma is a rare and aggressive germ cell tumor (GCT) that presents significant diagnostic challenges, particularly in males, where it is typically found in the gonads. Most patients present with advanced disease, often exhibiting symptoms related to metastatic spread, such as shortness of breath, cough, and hemoptysis. The rarity of extragonadal choriocarcinoma and its non-specific presentation make early diagnosis difficult, emphasizing the need for a multidisciplinary approach to treatment.
Case Presentation
A 31-year-old male presented with progressive shortness of breath, cough, and hemoptysis over a month. Initial imaging revealed multiple pulmonary nodules and a large necrotic retroperitoneal mass, along with liver metastases. The patient’s β-human chorionic gonadotropin (β-hCG) levels were markedly elevated, raising suspicion of choriocarcinoma, which was subsequently confirmed through biopsy. Given the rapid clinical deterioration, chemotherapy with Cisplatin and Etoposide was initiated. The patient responded well to treatment, with a significant reduction in tumor and metastasis size. Over 30 months of follow-up, the patient showed continued clinical improvement with no evidence of disease recurrence.
Conclusion
Extragonadal choriocarcinoma is a highly aggressive and rare malignancy that poses significant diagnostic and therapeutic challenges. This case underscores the importance of early intervention and the need for ongoing research to improve outcomes in these patients. A multidisciplinary approach is crucial for optimal management.