MULTIPLE ENDOCRINE NEOPLASIA TYPE-1 IN PATIENTS WITH RECOGNIZED PITUITARY-TUMORS OF DIFFERENT TYPES

OBJECTIVE We have investigated the prevalence of MEN 1 in patients wit h recognized pituitary adenomas, Since hyperparathyroidism is present in nearly 95-100% of patients with MEN 1 and frequently is the first c ondition to be identified, the study was limited to the identification of patients with hyperparathyroidism while the screening for gastroen teropancreatic (GEP) lesions was carried out in patients with both pit uitary and parathyroid lesions. PATIENTS AND MEASUREMENTS Serum total and ionized calcium, phosphate and intact PTH 1-84 (EASIA) were measur ed in 166 patients (68 with nonfunctioning pituitary adenoma, 42 with prolactinoma, 35 with GH-secreting adenoma, 17-with ACTH-screening ade noma, 1 with TSH-secreting adenoma, 1 with FSH-secreting adenoma and 2 with an only alpha-subunit secreting adenoma) referred to our clinic from 1990 to 1996, Plasma gastrin, somatostatin, pancreatic polypeptid e and vasoactive intestinal peptide were measured by RIA in patients w ith hyperparathyroidism. RESULTS Eight of 166 patients (4.8%) were fou nd to have primary hyperparathyroidism and among these 2 also had a ga strinoma while there was no evidence of other GEP tumours, Considering the tumour type, 6 had prolactinoma (14.3%), 1 GH-secreting adenoma ( 2.8%) and 1 non-functioning adenoma (1.5%), In most patients the diagn osis of pituitary tumour was made several years before that of hyperpa rathyroidism (from 1 to 15 years) although 6 patients had previously s uffered from urolithiasis and one had undergone gastric resections for recurrent peptic ulcers. One patient was identified as a MEN 1 gene c arrier and 2 had relatives with signs and symptoms referable to parath yroid or GEP lesions. CONCLUSIONS The study shows a prevalence of 4.8% of primary hyperparathyroidism in unselected patients with known pitu itary tumours similar to that reported in a previous study, By contras t, the prevalence of MEN 1 in patients with prolactinoma was definitel y high (14.3%), In most patients the diagnosis of pituitary tumours wa s made several years before that of hyperparathyroidism, Although the patients were believed to harbour a sporadic pituitary tumour, most of them had had signs and/or symptoms referable to one or both of the ot her organs involved in MEN 1, often concomitantly with those of pituit ary tumours, These data indicate that the diagnosis of MEN 1 syndrome is missed in a substantial proportion of patients with prolactinomas a nd therefore the. screening of these patients for the syndrome is stro ngly recommended.