Hyperparathyroidism.

Since the introduction of routine automated measurements of serum calcium levels in the 1970s, the detection of primary hyperparathyroidism has risen considerably. Nevertheless, the severe bone changes described by von Recklinghausen are still quite rare. The apparent rise in incidence is accounted for by the discovery of a large group of predominantly asymptomatic elderly patients who have mild primary hyperparathyroidism. Because the diagnosis is most often confirmed through laboratory tests, radiologic studies are now most useful in assessing the severity of the disease. The presence of bone changes is an accepted indication for parathyroid surgery in primary hyperparathyroidism. For patients with asymptomatic disease in whom nonsurgical treatment may be considered, radiographic evaluation is one of several techniques that may be used to assess progression. High resolution radiographs of the hands are most valuable in this regard. Accelerated bone mineral loss, as measured by quantitative techniques, will probably play a significant role in the future. Radiographic follow-up of patients with renal disease and secondary hyperparathyroidism is equally important, as increased bone or soft tissue changes may indicate a need for therapeutic change. Radiographically identifiable changes of hyperparathyroidism consist mainly of various types of accelerated bone resorption. Multifocal subperiosteal resorption is generally considered to be pathognomonic of hyperparathyroidism. Subligamentous, subchondral, endosteal, and intracortical resorption are also important manifestations of accelerated bone turnover. The earliest bone changes are visible in the hands and should be searched for especially carefully in the phalanges and terminal tufts. Only occasionally will changes be found elsewhere in the skeleton when hand changes are not present.