Fewer than 30 cases of parathyroid carcinoma(PC) have been described in renal hyperparathyroidism

A 67-year-old gentleman on long-term dialysis for chronic renal failure, history of multiple fractures of the ischio-pubic branches and mobilizing in a wheelchair was admitted for tertiary hyperparathyroidism and multinodular goiter. At admission calcium and PTH were respectively 3.01mmol/l and 1541pg/l despite calcimimetics. US-scan documented retrosternal multinodular goiter and a 20x27mm hypoechoic nodular mass at the left lower pole of the thyroid. 99mTC-MIBI scan showed elective concentration in the same position. CT scan showed multiple osteolytic lesions of the axial skeleton compatible with brown tumors. Working diagnosis was of tertiary hyperparathyroidism with suspect left lower PC. The patient underwent total thyroidectomy, central compartment dissection and total parathyroidectomy with parathyroid transplant.

The patient was discharged on the 12th postoperative day with PTH<6 pg/ml. Pathology revealed pT1N0 left inferior PC alongside parathyroid hyperplasia, and pT1aN1a multifocal papillary microcarcinoma in multinodular goiter. The patient is recurrence-free at five years follow-up, shows complete regression of osteodystrophy and is able to walk.

Combining MIBI and neck US-scan may increase diagnostic accuracy in detecting parathyroid cancer. In the less frequent case that PC is identified preoperatively or intraoperatively, en-bloc resection of the tumor, ipsilateral thyroid lobectomy and resection of adjacent paratracheal lymphatic tissue may reduce the need for repeat surgery and improve survival outcomes. Careful patient consent, preoperative dialysis to achieve normal kalemia, careful tissue manipulation and immediate postoperative dialysis are essential for a satisfactory outcome in parathyroidectomy for renal hyperparathyroidism.