Parathyroid gland morphology in nonparathyroid hormone-mediated hypercalcemia.

Occasionally, patients with other causes of hypercalcemia undergo parathyroidectomy for suspected primary hyperparathyroidism. We studied the parathyroid glands from 12 persons with nonparathyroid hypercalcemia. Glands from these individuals were similar to normal glands in size and fat:parenchymal ratio, showing neither atrophy nor hyperplasia. A distinctive histologic feature, also seen in hyperparathyroid hypercalcemia, is the presence of pale, vacuolated cells arranged in a trabecular pattern. Recognition of normal parathyroid parenchymal weight and the nonspecific nature of these vacuolated cells is necessary to prevent false-positive diagnoses of parathyroid hyperplasia. For glands which have not been weighted, parenchymal cross-sectional area can only be used as a rough index of parenchymal weight.