高位精巣摘除術後にヒト絨毛性ゴナドトロピンβ (hCG-β)が偽陽性を呈したStage Iセミノーマの1例

Abstract

A 21-year-old male presented at our hospital with a complaint of left scrotal swelling. The serum human chorionic gonadotropin-β (hCG-β) level was 1.3 ng/ml. A left high orchitectomy was performed, and a histological study demonstrated seminoma. Computerized tomography showed no evidence of metastasis. Adjuvant radiation therapy with 25 Gy was performed for stage I seminoma. Although complete clinical remission was achieved, the hCG-β level remained slightly positive (0.3-0.5 ng/ml). The urine hCG-β-core fragment was determined to be within normal limits. This confirmed that the result of serum hCG-β measurement was false-positive in our case. The patient received no additional treatment, and is free from recurrence 3 years and 1 month after surgery. In the testicular germ cell tumors, the measurement of urine hCG-β-core fragment is useful for differential diagnosis in cases of low level-positive serum hCG-β without clinical evidence of disease.