Normocalcemic primary hyperparathyroidism associated with progressive cortical bone loss - A case report.

The existence of normocalcemic primary hyperparathyroidism (NPHP) was acknowledged at the Third and Fourth International Proceedings on primary hyperparathyroidism PHPT but data relating to its clinical presentation, natural history, and skeletal status were limited and there was no information nor guidelines as to definitive therapy. Herein are reported biochemical, hormonal, and densitometry data in a postmenopausal woman seen initially for osteoporosis who was found to have increased serum PTH levels and normal serum total and ionized calcium levels without evidence of secondary hyperparathyroidism. Over a seven year period, the patient exhibited continuing preferential cortical bone loss at the one-third site of the radius in the face of relatively stable readings at the lumbar spine and hip that led to a subtotal parathyroidectomy for parathyroid hyperplasia with resultant normalization of serum PTH.