Parathyroid carcinoma is one of the rarest malignancies represented by around 0.005% of all cancers and 0.5%-1% of all parathyroid disorders patients. The occurrence is equal in both males and females, while other conditions, hyperparathyroidism, are more seen in females.

Parathyroid carcinoma has the signs of increasing calcium or parathyroid hormone levels. The symptoms can range from mild to severe, like fatigue, depression, or impaired memory, focus, or attention. Patients with parathyroid carcinoma have shown 10%-30% of having the metastatic disease linked to lung, bone, or liver.

The main criteria for treating parathyroid carcinoma are surgical resection, while En bloc resection with negative margins is one of the finest strategies for a cure. The research suggests that the survival rates for patients with complete en bloc resection with negative margins are 90% at 5 years and 67% at 10 years.

Adjuvant therapy with chemotherapy or external beam radiation is not proven to be effective. Recurrence is common, and reoperation is recommended or resectable recurrent disease. Many patients have disease recurrence after resection, with reported rates of 50%-100%.

Preoperative diagnosis is challenging and requires a high index of suspicion, with extremely elevated calcium or PTH levels, palpable neck mass, hoarseness, or lymphadenopathy evidence on preoperative imaging. Calcimimetic and bisphosphonate therapy can palliate symptoms of recurrence with intractable hypercalcemia.

Ref: https://ascopubs.org/doi/full/10.1200/JOP.19.00540