Akademik Veri Yönetim Sistemi
SN Comprehensive Clinical Medicine, cilt.7, sa.1, 2025 (Scopus)
Introduction: Testicular cancer is the most common malignancy in young males and is often associated with elevated tumor markers, including beta-human chorionic gonadotropin (bHCG). Extremely high bHCG levels can exhibit TSH-like activity, potentially leading to thyroid dysfunction. Recognizing this paraneoplastic phenomenon is crucial to prevent misdiagnosis and unnecessary interventions. Case Presentation: A 47-year-old male with metastatic testicular cancer was diagnosed with a mixed germ cell tumor and treated with four cycles of BEP chemotherapy. Initial laboratory tests revealed hyperthyroidism (suppressed TSH, elevated fT3 and fT4) without clinical symptoms. Thyroid imaging and autoantibody tests ruled out intrinsic thyroid disease. Markedly elevated bHCG (686,404 U/L) was identified as the cause of thyroid dysfunction due to its TSH-like effects. Following chemotherapy, both bHCG and thyroid hormone levels normalized without specific treatment for hyperthyroidism. Conclusions: This case underscores the importance of monitoring thyroid function in testicular cancer patients with elevated bHCG levels. Awareness of bHCG-induced thyroid dysfunction can help avoid unnecessary treatments and ensure appropriate management.