[Transient hyponatremia the first symptome of multiple endocrine neoplasia type 1 (MEN 1)--case report].

Transient character of laboratory abnormalities is usually explained as a false result of estimation. Spontaneous disappearance of laboratory abnormalities could be recognized as non-important and contradicting serious disease. Presented case of multiple endocrine neoplasia type 1 (MEN 1) denies these assumptions. Sixty-nine-years old woma was admitted to the internal department because of weakness, fever, dehydration and hypotension--symptom accompanying an upper respiratory infection. Moderate hyponatremia (122.6 mmol/l) was found in a routine laborator examination. All clinical symptoms as well as hyponatremia disappeared during hospitalization. Transient hyponatremi was not ignored. Further laboratory and hormonal investigations were performed. Fasting, morning serum cortisol concentration and 24-hours urinary excretion of free corticosterids were decreased and Synacten stimulation test reveale incomplete cortisol stimulation. Pituitary tumour was found in the CT scan. Moreover blood ionized calcium an parathyroid hormone were elevated. These results revealed secondary adrenal insufficiency, non-functioning pituitary tumor and hyperparathyroidism. Removal of pituitary adenoma was done. Asymptomatic hypercalcemia persists. Presented MEN 1 was atypical because: 1. Usually hyperparathyroidism is the first and most frequent symptom while in our patient the first symptom was transient hyponatremia secondary to the pituitary tumor, 2. was diagnosed in the old age while the majority of MEN 1 patients are younger, 3. asymptomatic course of hypercalcemia indicates that in some of elder patients removal of the parathyroid glands might not be necessary.