Abstract
INTRODUCTION: Primary mediastinal seminoma is a rare extragonadal germ cell tumor that poses significant diagnostic and therapeutic challenges, particularly in low-resource settings. Its nonspecific clinical presentation and limited access to advanced molecular diagnostics often delay definitive management. CASE PRESENTATION: A 21-year-old Indonesian male presented with progressive dyspnea and a persistent non-productive cough lasting three months. Imaging revealed a large anterior mediastinal mass. Diagnosis was established via ultrasound-guided core needle biopsy and immunohistochemical analysis, demonstrating CD117 positivity and CD45 negativity, consistent with mediastinal seminoma. Due to extensive tumor invasion and limited surgical infrastructure, only partial resection was feasible. The patient subsequently received 3 cycles of bleomycin, etoposide, and cisplatin (BEP) chemotherapy. He achieved full functional recovery and remains disease-free at three-year follow-up. DISCUSSION: This case underscores the feasibility of achieving favorable oncologic outcomes in resource-constrained environments through adaptive diagnostic and therapeutic strategies. The use of minimally invasive biopsy techniques and targeted immunohistochemistry enabled timely and accurate diagnosis. Pragmatic surgical decision-making, prioritizing patient safety over radical excision, followed by standard chemotherapy, resulted in durable remission. Multidisciplinary collaboration and longitudinal surveillance were critical to the patient's sustained recovery. CONCLUSION: Primary mediastinal seminoma can be effectively managed in low-resource settings through context-sensitive clinical approaches. This case highlights the importance of diagnostic adaptability, multidisciplinary care, and long-term follow-up in achieving successful outcomes for rare thoracic malignancies. Broader lessons include the value of pragmatic decision-making, judicious use of limited diagnostic tools, and structured follow-up strategies that can guide clinicians facing similar challenges in resource-limited environments.