Endocrine Abstracts

Introduction: We diagnosed multiple endocrine neoplasia type 1 (MEN1) based upon the occurrence of two primary MEN1 tumor types in patient without family history of MEN1. Hyperparathyroidism was diagnosed in patient five years after gastrinoma surgery. With hormone tests and morphologic investigation we excluded pituitary adenoma.

Case report: Forty-nine year old patient was admitted with abdominal pain and vomiting. Laboratory testing revealed elevated values of calcium 3.29 mmol/l (normal range 2.2–2.6 mmol/l), ionized-calcium 1.88 mmol/l (1.12–1.23 mmol/l) and intact parathyroid hormone 365 ng/l (10–65 ng/l). We performed ultrasonography of neck region and subtraction thyroid scan. Investigations showed multiple parathyroid adenomas. The patient was referred to thoracic surgeon. Two years ago, he was diagnosed whit kidney stones and was not referred to endocrinologist. In 2007, he was diagnosed with gastrinoma. Tumor was located in pancreatic head, there was no metastatic disease. Whipple operation was performed. At that point we excluded the possibility of MEN1 with laboratory testing.

Discussion: MEN1 is heritable disorder characterized by a predisposition to parathyroid adenomas, anterior pituitary adenomas and tumors of pancreatic islet cells. Multiple parathyroid adenomas causing hyperparathyroidism are the most common manifestation of MEN1 with almost 100% penetrance and in the most cases the initial manifestation. Pancreatis islet cell and gastrointestinal adenomas become clinically apparent in one-third of patient, approximately 60% have Zollinger–Ellison syndrome (ZES). ZES is initial clinical manifestation of MEN1 in 40% of patient. On the other hand, MEN1 is present in 20–60% of patients with ZES. Pituitary disease occurred in 60% of patients.

DNA testing for MEN1 gene mutations is available and can provide valuable information in specific situation.

Conclusion: Annually monitoring and biocemical screening in all patients with diagnosed MEN1-associated tumors has to be considered.