Objective: To determine, in a series of patients with secondary and tertiary parathyroid hyperplasia, whether the type of parathyroidectomy (subtotal, total with autotransplantation, or total), the histologic pattern of the parathyroid tissue, or the proliferative index, as determined by Ki-67 analysis, could predispose patients to recurrent hyperparathyroidism.
Summary background data: Recurrent hyperparathyroidism appears in 10--70% of the patients undergoing surgery for secondary or tertiary hyperparathyroidism. The incidence could be related to the type of operation (Rothmund) but also depends on the histologic pattern of the glands removed (Niederle).
Methods: The retrospective investigation was performed on 446 patients undergoing parathyroid surgery. They were also studied in relation to the possibility of renal transplantation. In this population, two homogeneous groups were subsequently identified (23 patients with clear signs of recurrence and 27 patients apparently cured); they were studied from the histologic and immunohistochemical point of view using antibody to Ki-67 antigen.
Results: Subtotal parathyroidectomy, total parathyroidectomy with autotransplantation, and total parathyroidectomy produced similar results when considering the regression of osteodystrophy, pruritus, and ectopic calcification. As one could anticipate, total parathyroidectomy increased the incidence of hypoparathyroidism. The percentage of recurrence was 5% to 8% after subtotal parathyroidectomy, total parathyroidectomy with autotransplantation, and total parathyroidectomy, and only after incomplete parathyroidectomy did this percentage climb to 34.7%. In the recurrence group, the nodular form was more common and the proliferative fraction detected by Ki-67 was 1.9%; it was 0.81% in the control group.
Conclusions: Because more radical procedures were not more effective, the authors favor a less radical procedure such as subtotal parathyroidectomy. Histologic patterns and proliferative fraction could be useful indices of a recurrence, and these patients should be watched closely after surgery.