A 48-year-old woman has severe primary hyperparathyroidism with calcium 15.2 mg/dL and intact PTH of 1450 pg/mL. Neck imaging suggests a large heterogeneous mass. At operation the lesion is hard, adherent to the thyroid and trachea, and histology shows fibrous bands traversing the tumour with capsular and vascular invasion. Which statement is correct?

• A Calcimimetic therapy should replace surgery as first-line treatment
• B Simple capsular enucleation is adequate because the tumour is benign
• C Radioiodine therapy is the preferred adjuvant treatment
• D En bloc resection with ipsilateral thyroid lobectomy offers the best chance of cure ✓

Explanation

These findings define parathyroid carcinoma, suggested preoperatively by calcium above 14 mg/dL and PTH several times the upper limit. It is a slow-growing malignancy that spreads locally and kills by uncontrolled hypercalcaemia rather than distant metastasis. En bloc resection of the tumour with the ipsilateral thyroid lobe and any invaded structures at first operation gives the best cure rate; breach of the capsule seeds recurrence. Calcimimetics such as cinacalcet are palliative for unresectable or recurrent disease.

Reference: Sabiston Textbook of Surgery, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.