Histological and clinical features of non-familial primary parathyroid hyperplasia

Relations between histopathological characteristics and clinical data were retrospectively investigated in patients with sporadic primary hyperparathyroidism due to hyperplasia. The study comprised 100 patients with chief cell hyperplasia and nine with hyperplasia of the water-clear cell type operated on during the period of 1959-1989. The chief cell hyperplasia was associated with a renal stone disorder as the predominant symptom in 41 patients, psychiatric/neuromuscular manifestations in 26 patients, while 23 patients were apparently asymptomatic. The remaining ten patients had miscellaneous symptoms. Patients with renal stones were more frequently of the male sex and generally had lower serum calcium values and less marked increments in total parathyroid glandular weights than patients with other symptoms or those who were overtly asymptomatic. Two main morphological patterns, diffuse and nodular hyperplasia, were encountered in chief cell hyperplasia. Diffuse hyperplasia was usually found in moderately enlarged glands, with a less variable size and morphology. It was also more prevalent among young patients having moderate hypercalcaemia and either recurrent renal stones or neuromuscular/psychiatric symptoms. The glands affected by nodular hyperplasia were asymmetric in size with a variable cellular arrangement and a high proportion of oxyphil cells. Nodular hyperplasia was irrespective of symptoms more frequent in the elderly patients. Water-clear cell hyperplasia was not encountered during the last decade of the study and until then it was an occasional finding in patients with marked hypercalcaemia. In this histological entity the glands were greatly and asymmetrically enlarged.