Synchronous Multiple Parathyroid Carcinoma: A Challenging Diagnosis Influencing Optimal Primary Treatment-A Literature Review to Guide Clinical Decision-Making.

Synchronous multiple parathyroid carcinoma is a rare condition within the already uncommon landscape of parathyroid malignancies, which comprise less than 1% of sporadic primary hyperparathyroidism cases. To date, only seven cases of synchronous multiple parathyroid carcinoma in sporadic primary hyperparathyroidism have been documented. This exceptional rarity complicates both the diagnostic process and therapeutic decision-making.