The first two authors contributed equally to this work.
Double adenomas (DAs) occur in 2–15 % of primary hyperparathyroidism (pHPT) patients. To date, the existence of this distinct entity remains controversial. The aim of this study was to evaluate the clinical characteristics and anatomic distribution of DAs to identify anatomic patterns and implications for surgical management.
We reviewed prospective database records of 1,464 unselected, consecutive patients who were treated for pHPT in our institution between 1986 and 2012. We identified 100 DA patients (6.8 %) and compared their clinical characteristics with those of solitary adenomas (SAs; n = 1,226) and hyperplasia (including multiple endocrine neoplasia; n = 101).
A total of 74 % of our patient collective was female. DAs were predominantly located on the right side (30 %) or crossed (23 %) and demonstrated an increased incidence of atypical position (38 %). Patients with DA showed significantly more neuropsychiatric disorders and pancreatitis compared with those in the other groups. Our results revealed higher parathyroid hormone levels in patients with DA compared with those with SA or hyperplasia. In 74 patients, the DA was primarily found, whereas 26 patients needed reoperation. Only nine DAs had developed metachronously. The overall cure rate of all patients with pHPT was 96.4 % (carcinomas excluded).
DAs are a distinct entity and show no specific characteristic features that could facilitate easy detection. The chance of a metachronous appearance is statistically low, but has significant clinical impact as a major cause for late recurrence of hyperparathyroidism and need for reoperation.