Identification of multiple endocrine neoplasia type 1 in patients with apparent sporadic primary hyperparathyroidism.

Background: In the evaluation of patients with primary hyperparathyroidism (PHP), specific query for a personal or family history of MEN1 (Hx) is recommended widely, but responses are rarely positiv. We instituted a 6-question panel (6Q) to routinely screen for MEN1 preoperatively.

Methods: The clinical database entries of 939 patients explored for apparent sporadic PHP from June 1992 to November 2007 were examined for presenting diagnosis, demographics, anatomic findings, MEN1 analysis, and final diagnosis. To directly compare the results of 6Q and Hx, we also reviewed the charts of 654/939 PHP patients screened systematically from January 2000 to November 2007.

Results: MEN1 was undiagnosed until the preoperative evaluation in 1.6% of patients referred with apparent sporadic PHP. To date, MEN1 has been diagnosed in 42 of 939 (4.5%) PHP patients. Compared with those who have sporadic PHP, MEN1 patients were often male (38.1% vs 20.2%; P = .005) and young (mean, 38 +/- 17 years vs 60 +/- 13 years; P < .001). When hyperplasia was present at initial parathyroid exploration, the likelihood of MEN1 was 26% (32/123). For the 15 patients diagnosed by a surgeon to have MEN1, Hx was positive in 3 patients (20%) and 6Q in 13 (87%) (P = .0002). In a multivariate analysis of 635 patients with negative Hx, the likelihood of MEN1 increased with (1) younger age at initial parathyroid exploration and (2) number of positive 6Q responses.

Conclusion: MEN1 occurs relatively often and can be missed. Systematic use of a simple 6-question panel helps to identify MEN1 prior to parathyroid exploration. Young male patients with parathyroid hyperplasia and positive 6Q results should be evaluated for MEN1.