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.
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.
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.
Frontiers in oncology. 2024 Mar 27*** epublish ***
Diletta Favero, Christoph Oing, Christoph Seidel, Pasquale Rescigno, Fabio Catalano, Malvina Cremante, Sara Elena Rebuzzi, Federico Gatto, Giovanni Rosti, Diego Ferone, Giuseppe Fornarini, Francesco Cocchiara
Department of Internal Medicine and Medical Specialties (Di.M.I.), School of Medicine, University of Genova, Genova, Italy., Translational and Clinical Research Institute, Centre for Cancer, Newcastle University, Newcastle upon Tyne, United Kingdom., Department of Oncology, Hematology and Bone Marrow Transplantation with Division of Pneumology, University Medical Centre Eppendorf, Hamburg, Germany., Medical Oncology Unit 1, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Policlinico San Martino, Genova, Italy., Medical Oncology Unit, Ospedale San Paolo, Savona, Italy., Endocrinology Unit, Department of Internal Medicine, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Policlinico San Martino, Genova, Italy., Oncology Department, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Pavia, Italy., Endocrinology Unit, Department of Internal Medicine and Medical Specialties (Di.M.I.), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Policlinico San Martino, University of Genova, Genova, Italy.