Primary hyperparathyroidism

Primary hyperparathyroidism is a quite frequent disease, the incidence of which has been found to increase over the past two decades. At the same time there has been a remarkable change in its clinical presentation; therefore this endocrine disorder earlier considered rare but almost always associated with complications, now appears a quite common and uncomplicated disease. In our series of 150 patients diagnosed between l966 and l989 the female/male ratio was found to be l.77. The ratio has significantly increased (2.09), beginning from l983; this was mainly due to the availability of a bone densitometer at our Mineral Metabolism Service with consequent greater demand of serum calcium determination as a part of routine metabolic screening for prevention of postmenopausal osteoporosis. Whilst the percentage of patients with renal manifestations of the disease has not significantly changed during these years, the amount of asymptomatic patients (yrs l966-l983 = 3.7% vs yrs l984-l989 = 39.7%) has progressively increased to the detriment of patients with skeletal symptoms. Serum intact parathyroid hormone determination by immunoradiometric assay (and possibly by immunochemiluminometric assay) seems to have overcome some of the methodological problems inherent in conventional radioimmunoassay. Surgical treatment of primary hyperparathyroidism is safe and highly effective in experienced hands. Recurrence has been observed only in three cases after resection of parathyroid adenoma, thus indirectly supporting a monoclonal origin of the tumor. Medical behaviour (conservative or surgical management) in respect to patients with the mild or asymptomatic form of the disease, especially when diagnosed in old age, is uncertain at this point in time. Future prospective studies carried out on a large number of patients are needed to better clarify this issue.