Isolated ectopic production of the free beta subunit of chorionic gonadotropin by an epidermoid carcinoma of unknown primary site
Isolated ectopic production of the free beta subunit of chorionic gonadotropin by an epidermoid carcinoma of unknown primary site
复制标题
原发部位不明的表皮样癌单独异位产生绒毛膜促性腺激素游离β亚基
作者：
MD STEVEN B. NAGELBERG;MD BARRY MARMORSTEIN;Ph. M. B. Khazaeli;P. M. SAUL W. ROSEN
一名39岁女性在产后7个月出现疲劳、盆腔疼痛、大量胸腔积液以及尿妊娠试验阳性，被怀疑患有转移性绒毛膜癌。随后的评估发现，一种广泛分布的低分化表皮样癌孤立地产生绒毛膜促性腺激素的游离β亚单位（CG -β）。化疗无效，该女性死亡，尸检时无法确定肿瘤的原发部位。患者的血清（185纳克/毫升）和一个肿瘤转移灶（720纳克/克）含有大量免疫活性物质，其稀释曲线与CG -β标准品平行，但未检测到绒毛膜促性腺激素（CG）、其α亚单位以及其他胎盘蛋白。一种能识别游离CG -β但不识别完整CG的单克隆抗体，在获得组织诊断之前有助于推断CG -β的异位来源。当患者的血清在葡聚糖凝胶上进行色谱分析时，CG -β免疫活性在比标准CG或CG -β表观分子量更高的位置洗脱，这表明该肿瘤分泌了一种改变了分子形式的CG -β亚单位。
Metastatic choriocarcinoma was suspected in a 39‐year‐old woman who presented 7 months postpartum with fatigue, pelvic pain, a massive pleural effusion, and a positive urine pregnancy test. Subsequent evaluation resulted in discovery of the isolated production of the freeβ‐subunit of chorionic gonadotropin (CG‐β) by a widespread, poorly differentiated epidermoid carcinoma. Chemotherapy was ineffective, the woman died, and at autopsy the primary site of the tumor could not be determined. The patient's serum (185 ng/ml) and a tumor metastasis (720 ng/g) contained large amounts of immunoactive material that diluted in parallel to CG‐β standard, but neither chorionic gonadotropin (CG), its alpha subunit, nor other placental proteins were detected. A monoclonal antibody that recognizes free CG‐β, but not intact CG, was instrumental in implicating an ectopic source of the CG‐β before a tissue diagnosis was obtained. When the patient's serum was chromatographed on a dextran gel, the CG‐β immunoactivity eluted in a position of higher apparent molecular weight than either standard CG or CG‐β, suggesting that this neoplasm secreted an altered molecular form of the CG‐β subunit.