Background: Primary hyperparathyroidism (HPT) is the most common endocrinopathy in MEN1 and usually its first clinical manifestation. Yet MEN1 is a rare disease, representing only 24% of all cases of HTP. We studied the frequency of MEN1 syndrome in HPT patients admitted to our Department.
Methods: In a retrospective analysis of 84 suspected HPT patients hospitalized in 19992006, case reports of 11 patients with suspected MEN1 were analysed. MEN1 was stated if two of the three main MEN1-related endocrine tumours occurred.
Results: HPT diagnosis was confirmed in 69 patients: of mean age 55.4±14.1 yrs. Median values of PTH and total calcium concentration were 57.4 pg/ml (min 60.6, max 1580) and 2.95 mmol/l (min 2,2, max 4,0), respectively. In parathyroid scintigraphy equivocal tracer accumulation was found in 72% of cases. MEN1 was diagnosed in 9 patients of mean age 51.3±12,0 yrs, in 8 of whom (89.0%) HPT was confirmed. Pituitary adenoma was found in 7 patients: 3 prolactinomas, 1 acromegaly, 1 Cushing disease and 2 non-functioning tumours. In 2 patients pancreatic tumours were diagnosed: somatostatinoma and gastrinoma were confirmed by laboratory tests and immunohistochemistry. Four carcinoids: 3 gastric and one bronchial were found. Mean 5-HIAA (5-hydroxyindoloacetic acid) urine excretion in the carcinoid patients was 144.0 μmol/24hrs (norm: up to 40), mean serum concentration of CgA (chromogranin-A) 728.7 U/L (norm: up to 18.0). Moreover, in the patient with HPT and somatostatinoma concurrent von Recklinghausens disease was diagnosed and in the HPT and prolactinoma patient, meningioma was found. Adrenal tumours were observed in two cases: one pheochromocytoma and one non-functioning tumour.
Conclusions: The frequency of MEN1 occurrence in our patients (13%) is much higher than that quoted in the literature (24%), clearly, due to referral of complicated cases to our Department. Patients with symptoms atypical for HPT should be screened towards MEN1.