[Endocrine abnormalities in a young patient with metastatic cancer - case 3/2013]

Abstract

History and admission findings: We report on a 24-year-old male patient who presented with worsening of the general condition and abdominal pain.

Investigations: On physical examination, gynecomastia was noted. Laboratory tests showed manifest hyperthyroidism. The beta-hCG levels were markedly increased. By ultrasound, the thyroid gland was hyperperfused without thyroid nodules. Several large echo mixed lesions were found in the liver. The testes appeared normal.

Diagnosis: In light of the typical laboratory findings, a non-seminomatous extragonadal germ cell tumor was diagnosed. Hyperthyroidism was most probably HCG induced.

Treatment and course: Initially the patient was treated with thyreostatic drugs. After initiation of chemotherapy and a marked decrease in beta-hCG, thyreostatic therapy could be terminated.

Conclusions: Germ cell tumors may cause an increase in beta-hCG concentration. By cross-reacting with the TSH-receptor this could induce hyperthyroidism. Germ cell tumors are therefore a rare differential diagnosis of hyperthyreoidism.