Differences in single gland and multigland disease are seen in low biochemical profile primary hyperparathyroidism.

BACKGROUND: Primary hyperparathyroidism is characterized by increased levels of serum calcium and parathyroid hormone. Recently, 2 additional mild biochemical profiles have emerged, normocalcemic and normohormonal primary hyperparathyroidism. We reviewed our surgical experience of mild biochemical profile patients and compared them with classic primary hyperparathyroidism patients.

METHODS: This is a single institution, retrospective cohort review of all patients who underwent parathyroidectomy for primary hyperparathyroidism from 2006-2012. Preoperative and intraoperative variables were analyzed. Univariable analysis was performed with analysis of variance and the χ2 test. A logistic regression was performed to identify significantly independent predictor variables for multigland disease.

RESULTS: A total of 573 patients underwent parathyroidectomy for primary hyperparathyroidism (classic, n = 405; normohormonal, n = 96; normocalcemic, n = 72). Normocalcemic primary hyperparathyroidism was associated with multigland disease in 43 (45%, P < .001) patients as compared with the normohormonal (7, 10%) and classic (36, 9%) groups. On logistic regression, significant predictors for multigland disease were the normocalcemic subtype and positive family history. Twelve month biochemical normalization rates after operative treatment were >98% in all 3 groups.

CONCLUSION: Our series shows that normocalcemic primary hyperparathyroidism is associated with a high incidence of multigland disease. Normohormonal disease is similar to classic disease patients with >90% presenting with single adenomas. Excellent rates of biochemical normalization can be obtained by operative treatment in all 3 groups.