Two case reports of parathyroid carcinoma and review of the literature

Parathyroid carcinoma is an infrequent endocrine malignant neoplasm with an aggressive behavior. Two cases of parathyroid carcinoma are described, one with a late diagnosis after previous surgeries for parathyroid hyperplasia, and the other diagnosed after pathologic fracture. The aim of this article is to make a review on recent parathyroid carcinoma literature and discuss these two illustrating cases. There has not been established any etiology for parathyroid carcinoma and no predisposing factors were identified. Parathyroid carcinoma may occur sporadically or as part of a genetic syndrome. The clinical features of parathyroid carcinoma are similar to benign cases of hyperparathyroidism and the pathologic diagnose is difficult. In the absence of metastatic disease in addition to a similar clinical setting, it can be difficult to distinguish benign and malignant hyperparathyroidism. Parathyroid carcinoma is a rare disease which diagnose can be challenging. Recent advances in immunohistochemical analysis may have helped in histopathologic evaluation, but pre-operative detection relies on imaging exams that may not differentiate malignant from benign hyperparathyroidism. The first surgical approach is paramount for disease control. There is still few effective therapeutic options for recurrent and metastatic disease, and these patients' prognostic status remain poor. Promising results were observed with denosumab and PTH immunization, and they may be a useful therapy for advanced cases in the future, but further investigation is required.