Successful Multimodal Treatment of Locally Advanced Parathyroid Carcinoma.

Parathyroid carcinoma is a rare endocrine malignancy for which the primary treatment is surgery; however, 50% of the patients develop local recurrence or distant metastases. No consensus exists on the standard treatment for metastatic parathyroid cancer. Here we report a case of a 41-year-old male with inoperable locally advanced parathyroid carcinoma who was successfully treated with multimodal therapy including radiofrequency ablation (RFA), external beam radiation therapy (EBRT) to the neck, and sorafenib. Eleven months after initiating sorafenib, serum calcium levels were normal, and both the intact PTH level and the size of metastatic lesion remained stable; thus, we decided to discontinue sorafenib. After discontinuation, the disease remained stable for 18 months and continues to be so. Hence, clinicians can consider multimodal treatment with RFA, EBRT, and sorafenib as a treatment option for locally advanced parathyroid carcinoma.