Hyperthyroidism in men with germ cell tumors and high levels of beta‐human chorionic gonadotropin

Abstract

A retrospective review was done on all high volume choriocarcinomas and other germ cell tumors of men with serum beta-human chorionic gonadotropin (beta-HCG) levels greater than 50,000 mIU/ml to determine the incidence and characteristics of hyperthyroidism in this setting. Nineteen patients were identified with high beta-HCG levels, but because 2 did not have thyroid function tests performed, the cases of only 17 patients were evaluable. Of these, 14 (82%) had primary testicular carcinoma and 3 (18%) had extragonadal tumors. Beta-HCG levels on presentation ranged from 80,000 to 3,058,000 mIU/ml, with a median of 243,500 mIU/ml. Seven of the 17 evaluable cases (41%) had T, serum levels higher than 12 pg/dl (normal level 4 to 12 pg/dl) with a median value of 15.4 pg/dl (range, 12.6 to 33.5 pg/dl); serum T, levels correlated with beta-HCG levels (r = 0.84). All seven patients with elevated T, levels had beta-HCG values greater than 200,000 mIU/ml, and three of these seven had clinical manifestations that could be attributed to an elevated serum T , ; only one patient required specific antithyroid treatment; and after control of primary disease, all other patients had normalization of thyroid function. The most common manifestations of hyperthyroidism in our series were tachycardia, hypertension, and a systolic flow murmur; none of the patients had thyroid gland enlargement. We conclude that subclinical hyperthyroidism is a relatively common phenomenon in germ cell tumors of men with high levels of beta-HCG and that control of the primary disease results in serum T, level normalization.

TSH and Thyrotropic Agonists: Key Actors in Thyroid Homeostasis

“…In cases of extremely elevated HCG levels, for example, in hydatidiform mole or chorionic carcinoma, overt hyperthyroidism and even thyroid storm may ensue [329–331]. The same pathomechanism may lead to hyperthyroidism in embryonal testicular carcinoma [332, 333]. …”

Paraneoplastic hyperthyroidism

“…HCG and TSH have 85% similarity on the first 114 amino acids, so that HCG is able to stimulate the TSH receptor 1. The first case of HCG-induced hyperthyroidism in a male was published in 1964,2 the association between high levels of HCG and hyperthyroidism has been documented repeatedly since then 3. In a recent study from the Netherlands, 144 male patients with metastatic non-seminomatous germ cell cancer in whom thyroid function tests were performed were evaluated 4.…”

Consenso brasileiro para o diagnóstico e tratamento do hipertireoidismo: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

“…The production of very high levels of hCG can stimulate the TSH receptor and thus cause hyperthyroidism in patients with choriocarcinoma, molar pregnancy (hydatidiform mole), or testicular cancer (216)(217)(218) (C,C,B). The differential diagnosis with other causes of thyrotoxicosis is based on low thyroid 131 I uptake, high serum gonadotropin levels, and presence of the corresponding producing tumor.…”