A comparison of outcomes for younger and older adult patients undergoing surgery for primary hyperparathyroidism

Background. In adolescents and young adults, primary hyperparathyroidism (PHPT) is an uncommon diagnosis. We compared the clinical characteristics of these patients to those of older adult patients with PHPT. We hypothesized that PHPT in adolescents and young adults is more often caused by single-gland disease and is amenable to minimally invasive parathyroidectomy (MIP). Methods. We retrospectively reviewed the medical records of 452 consecutive patients who had surgery for PHPT. Patients ranged in age from 13 to 94 years and were dichotomized into younger (age <30 years, n = 17, 3.8%) and older (age ≥30 years, n = 435, 96.2%) patients. Continuous baseline and intraoperative and postoperative measures were not normally distributed and were summarized with medians and interquartile ranges (IQRs). Groups were compared using Wilcoxon rank sum test or Fisher exact test, and significance was set at P<.05. Results. Median [IQR] age was 24 [23-27] years for the younger group and 58 [51-66] years for the older group. Though not statistically significant, a smaller proportion of the younger patients compared with the older patients had a positive ^99mTc-sestamibi scan (71%; 95% confidence interval [95% CI] = 44-90% vs. 83%; 95% CI = 79-86%) and showed a suspected parathyroid adenoma on ultrasound (65%; 95% CI = 38-86% vs. 80%; 95% CI = 76-83%). The younger and older age groups did not significantly differ on preoperative serum PTH levels (median [IQR]: 111 [76-145] pg/ml vs 110 [84-152] pg/ml; P = .73 respectively). The younger group had higher serum calcium levels (11.6 [11.1-12.2] mg/dl) compared with the older group (11.1 [10.7-11.5] mg/dl; P = .01). MIP was performed less frequently on the younger patients (70.6%) compared with older patients (88.7%; P = 0.04). Though the incidence of a single adenoma was somewhat more frequent in older patients (90%; 95% CI = 87-93%) than in younger patients (82%; 95% CI = 57-96%) it was the most frequent cause of PHPT in the younger patients. The younger and older groups did not significantly differ on percent drop from baseline for intraoperative PTH monitoring (81.7 vs 79.3%; P = .46), respectively. Conclusions. Younger patients with PHPT present with significantly higher serum calcium levels than older patients. However, younger patients are less likely to localize abnormal parathyroid glands on sestamibi or ultrasound. Though younger patients appear to have a higher incidence of hyperplasia compared with older patients, single gland disease is still the overall most frequent cause. Our data suggest that MIP should be more frequently considered in younger patients because of the high incidence of single gland disease.