Recurrence in parathyroid hyperplasias owing to secondary hyperparathyroidism is predicted by morphological patterns and proliferative activity values

The histological pattern and the cell proliferative activity (as detected by Ki-67 immunostaining) of a series of 50 parathyroid hyperplasias (PTHs) secondary to renal failure were studied to assess their value in predicting recurrence of hyperparathyroidism (HPT). On account of their clinical evolution, these cases were divided into two groups: recurrent HPT (23 cases) and nonrecurrent HPT (27 cases). A nodular growth pattern (as opposed to diffuse) was the prevalent one and was observed in 20 (74%) cases of nonrecurrent HPT and in 22 (95.6%) cases of recurrent HPT, a statistically significant difference (p < 0.05). The Ki-67 proliferative fraction was 1.9% in recurrent HPT cases, as compared with 0.81% in nonrecurrent HPT, a difference which was statistically significant (p = 0.001). We conclude that a nodular pattern of growth and an elevated Ki-67 proliferative fraction (>1.5%) in PTH are both associated with a higher risk of recurrence (4.30) of HPT.