%0 Case Reports
%T Hyperthyroidism in non-seminomatous testicular germ cell tumors: two case reports and literature review.
%A Favero D
%A Oing C
%A Seidel C
%A Rescigno P
%A Catalano F
%A Cremante M
%A Rebuzzi SE
%A Gatto F
%A Rosti G
%A Ferone D
%A Fornarini G
%A Cocchiara F
%J Front Oncol
%V 14
%N 0
%D 2024
%M 38601761
%F 5.738
%R 10.3389/fonc.2024.1338438
%X <B>UNASSIGNED: </B>Human chorionic gonadotropin (hCG)-induced hyperthyroidism is a rare paraneoplastic syndrome observed in non-seminomatous testicular germ cell tumors, due to a cross-reaction between the β-subunit of hCG with the thyroid-stimulating hormone receptor. The precise prevalence of this paraneoplastic phenomenon is unclear as, in the majority of cases, hyperthyroidism remains subclinical.<BR><B>UNASSIGNED: </B>Here, we present two cases of advanced metastatic non-seminomatous testicular germ cell tumors where patients exhibited signs and symptoms of thyrotoxicosis at primary diagnosis due to excessive serum β-hCG elevation, with complete remission of symptomatology after the start of oncological treatments and no signs of relapse at the time of publication of this report. Additionally, we provide a comprehensive review of the existing literature concerning this uncommon occurrence.<BR><B>UNASSIGNED: </B>Despite being a rare event, the presence of hyperthyroidism or thyrotoxicosis without clear etiology in a young man should lead to consider less frequent causes such as testicular tumors. Even if patients typically have mild symptoms that resolve after chemotherapy, in rare cases, it can be a life-threatening condition that requires prompt recognition and specific intervention.