Normacalcaemic primary hyperparathyroidism with osteitis fibrosa.

THE diagnosis of primary hyperparathyroidism has been classically based upon the demonstration of high plasma calcium and low plasma phosphorus concentrations and an excessive urinary excretion of calcium. In recent years, however, it has become recognized that patients with primary hyperparathyroidism may present with plasma calcium concentrations that are within the normal range (George et al., 1965; Nichols & Flanagan, 1967; Wills et al., 1969). In these reports the patients had all presented with a long history of recurrent renal calculi and excessive urinary excretion of calcium. The only previously reported cases of normocalcaemic primary hyperparathyroidism with osteitis fibrosa, of which we are aware, were recorded by Mather (1953) and Eisenberg & Gotch (1968). We report here a third case of normocalcaemic primary hyperparathyroidism with overt osteitis fibrosa.