The case report describes the case of 15-year-old patient in whom hypoglycaemia was diagnosed as the first manifestation of multiple endocrine neoplasia type 1 (MEN 1). There was MEN 1 manifested at three endocrine organs at the time of diagnosis (insulinoma, microprolactinoma and primary hyperparathyroidism).
Diagnosis was confirmed by genetic testing, family occurrence wasn't found.