Human Chorionic Gonadotropin as a Marker of Parathyroid Carcinoma: Findings From a Scoping Review.

Parathyroid carcinoma is an extremely uncommon cause of primary hyperparathyroidism; however, it is associated with excess morbidity and mortality. With the similarity in presentation from benign etiologies (such as an adenoma or hyperplasia), there is often a delay in diagnosis and initiation of treatment. Currently, there are no approved biomarkers to assist in the diagnosis of carcinoma. Over the last century, limited studies have investigated the role of human chorionic gonadotropin (hCG), particularly in its ability to differentiate cancerous from benign parathyroid disease. We performed a scoping review to analyze the existing literature regarding hCG (serum, urine, and histochemical staining) and its role in identifying malignant parathyroid disease. Across three databases and an endocrine abstract repertoire, we identified seven relevant articles meeting the prespecified inclusion criteria. We highlighted the normal physiology of hCG, alongside the pathophysiological expression and the rationale for its use as a biomarker for parathyroid cancer. Each article was analyzed, with emphasis on the methodologies, outcomes, and limitations. Although promising, the role of hCG as a biomarker has not been established due to heterogeneous methodologies and limited studies, which prohibit a firm conclusion. Further research (including larger prospective studies) is required to validate the role of hCG as a biomarker for parathyroid carcinoma.