Primary hypothyroidism in a patient with germ cell tumor: A case report

Germ cell tumors (GCTs) are known to present with thyroid dysfunction, typically manifesting as hyperthyroidism due to human chorionic gonadotropin secretion. However, hypothyroidism among GCT patients is a relatively underexplored phenomenon, which could be attributable to low clinical suspicion and the potential masking of hypothyroidism by cancer-related symptoms. Moreover, the impact of hypothyroidism on cancer-related outcomes remains uncertain. Here, we present a case of incidentally detected primary hypothyroidism in a 16-year-old girl with an ovarian GCT. Remarkably, her condition improved at an unexpected rate after cancer-directed treatment. In our evaluation, we identified various causes of reversible hypothyroidism, all of which are comprehensively reviewed in this case report.