Endocrine Abstracts

Introduction: Primary hyperparathyroidism (PHPT) is commonly the most early manifestation of multiple endocrine neoplasia syndrome type 1 (MEN1), but it can also occur in young patients without any inherited disorders. The aim of our study was to compare the clinical characteristics of PHPT in young patients with MEN1 syndrome and with sporadic disease.

Patients and Methods: The study included 72 patients with MEN-1 associated PHPT and 168 patients with sporadic disease. All patients were tested for MEN1 mutations. Electronic medical records were used to analyze clinical data of each patient. Patients who had sufficient data at the time of manifestation of PHPT (before the first surgery) were included.

Results: Both groups consisted mostly of young patients and there was no significant difference in the age of manifestation: 31 [25; 39] in the MEN1-group vs 34 [29; 37] in sporadic PHPT (P=0.308). We did not receive a difference in preoperational levels of parathormone (145.2 pg/ml [98.7; 227.0] in MEN1 group and 152.07 pg/ml [113.90; 241.38] in sporadic PHPT, P=0.248, as well as in albumin-corrected total blood calcium, phosphorus, and daily calciuria (p>0.05 for all)). Also, no statistical difference was found in postoperative levels of PTH (P=0.605) and total blood calcium (P=0.466). Our groups did not differ in the prevalence of nephrocalcinosis/nephrolithiasis (59% in the MEN1group and 63% in the sporadic PHPT, P=0.615). Bone mineral density less than -2.0 SD (Z-score) was found more often in MEN1group: 54 vs 34% in sporadic patients, P=0.031. There were significant differences in the preoperative number of the parathyroid (PT) tumors at the time of the primary surgery (95% of patients with sporadic PHPT and 41% of patients in the MEN1 group had only one PT tumor preoperatively, P<0.001). Differences were also obtained by histological characteristics of the PT tumors (the frequency of adenoma, hyperplasia, and carcinoma occurrence (P<0.001)), recurrence of PTHT after the surgery (36% of patients in MEN1 group and 1% in sporadic PHPT, P<0.001), and family history of other endocrine neoplasia (69% of patients in MEN1 group and 18% in the sporadic PHPT, P<0.001).

Conclusion: Number of PT tumors, their histological characteristics, recurrence rate and family history should be taken into consideration when evaluating young patients with PHPT.