Abstract #1409027: Paraneoplastic Hyperthyroidism

Non-seminomatous germ cell tumors producing human chorionic gonadotropin (HCG) were first described in 1964. HCG is capable of inducing hyperthyroidism by stimulating the TSH receptor, due to its identical alpha subunit. We report a case HCG-mediated setting choriocarcinoma. A 28-year-old man presented with 3-week history unintentional weight loss, cough, hemoptysis, palpitations, shortness breath, nausea and vomiting. Chest x-ray showed large pleural effusion multifocal nodular opacities on lungs measuring up 4 cm. CT abdomen/pelvis 1.4 cm left renal mass concerning for metastasis, hepatomegaly. chest demonstrated 16 heterogeneous enhancing mediastinum, pericardial effusion, moderate metastatic pulmonary nodules. Laboratory results elevated 947,825 mIU/mL, AFP 25 ng/ml, LDH 1,394 U/L, 0.011 mcIU/mL, FT4 2.0 ng/dL, Ferritin 2680 ng/mL, CRP 118 mg/L. Testicular ultrasound was unremarkable. Biopsy mediastinal consistent Endocrinology consulted evaluation abnormal thyroid function. He tachycardic, without other overt symptoms no clinical findings Graves’ Disease. TRAB, TSI, TPO antibodies negative. Propylthiouracil (PTU) 100mg every 8 hours low dose propranolol started. Chemotherapy Etoposide, Ifosfamide, Cisplatin initiated. Thyroid function improved 5 days after initiation therapy. After 3 cycles chemotherapy, his Free T4 levels normalized level decreased 1,521 mIU/mL. His most recent tests 5.8 mcIU/ml 1.1 ng/dL decision made stop PTU. heterodimer an subunit that TSH, LH FSH. High can stimulate receptor cause hyperthyroidism. Hyperthyroidism has been reported trophoblastic when are >200,000 Initiation chemotherapy produces rapid decline improvement levels. Diagnosis paraneoplastic challenging, as may overlap those disease. Symptomatic patients should be started thianomide beta blocker which improve well-being tolerance chemotherapy. illustrated challenge diagnosing HCG-secreting choriocarcinoma importance initiating anti-thyroidal medication symptomatic outcomes.