LAUSR

Purpose Ectopic parathyroid glands are thought to be the cause of a significant portion of failed primary surgery for hyperparathyroidism. Parathyroid carcinoma (PTCA) is a rare malignant tumor, and ectopic PTCA is a particularly unusual situation. Here, we describe, for the first time, a case of intrapericardial PTCA. Methods We describe the case of a 53-year-old female presented with 1-year history of backache, multiple fractures, nephrolithiasis, nausea, vomiting, fatigue, and unexplained myocardial ischemia-like symptoms. Physical examination revealed a barrel chest and sternal tenderness with stable vital signs. Blood tests confirmed hypercalcemia (3.70 mmol/L) and hyperparathyroidism (>1900 pg/ml). 99m Tc-sestamibi scan indicated ectopic findings in the mediastinum highly suggestive of parathyroid adenoma. Results After more tests, cardiac magnetic resonance imaging (MRI) revealed a mass closely related to the great vessels of the heart. The ectopic tumor in the pericardium was successfully resected through sternotomy, with subsequent histopathological confirmation of PTCA. The metabolism of calcium and phosphorus and the level of PTH returned to normal after surgery. Conclusion This unique case reinforces the tremendous variety of possible ectopic locations of parathyroid glands. Although most patients with primary hyperparathyroidism (PHPT) carry a high suspicion of a benign course, the entity of ectopic PTCA also needs to be considered. Accurate preoperative locating diagnosis as well as en bloc tumor resection offers the highest chance of cure in patients with PHPT.