PAPILLARY PARATHYROID ADENOMA - A RARE OCCURRENCE AND ITS IMPORTANCE IN DIFFERENTIATION FROM PAPILLARY CARCINOMA OF THE THYROID

The case of a 67-year-old woman with primary hyperparathyroidism manif ested by hypercalcemia with anorexia, nausea, and weakness; low serum phosphorus; high circulating parathyroid hormone; and mildly elevated calcitriol and parathyroid hormone-related protein is reported. A cyst ic lesion was removed from the inferior pole of the right lobe of the thyroid, and serum calcium levels rapidly returned to normal. The lesi on was proven histologically to be a parathyroid adenoma with predomin ate papillary features. The differentiation of such a rare lesion from papillary carcinoma of the thyroid, both histologically and cytologic ally, is stressed.