Endocrine Abstracts

Introduction: An insulinoma is a neuroendocrine tumor, deriving mainly from pancreatic islet cells, that constantly produces insulin even when blood sugar is very low. Insulinomas are the most common cause of hypoglycemia resulting from endogenous hyperinsulinism. Biochemical diagnosis of insulinoma is established during prolonged fasting test (up to 72 hours) in 95 % of patients, 90-95% of insulinomas can be diagnosed during 48 hours of prolonged fasting. After biochemical confirmation of the existence of insulinoma, imaging studies are used to localize the tumor.

Material and methods: A female patient aged 54 years, mother of two children, no smoker. In menopause from 3 years ago. She has arterial hypertension from the past disease, regulated by an angiotensin receptor blocker. The patient consults the ambulant of Endocrinology Clinic due to symptoms of malaise, fatigue and tingling in the mouth, which occurred episodically and improved after ingestion of carbohydrates. During one such episode, glycaemia was measured at 2 mmol/l. She gives information that she does not remember events from the recent past. On one occasion she lost consciousness. These symptoms were started a year ago, so the patient was examined by a neurologist and the existence of neurological disease has not been established. From the outpatient analysis fasting plasma glucose 3.1 mmol/l, HbA1C: 4.4 %, OGTT: O min: 4.6 mmol/l, 120 min: 1.5 mmol/l, due to suspicion of insulinoma the patient is hospitalized for additional examination.

Тhe diagnosis is made by a prolonged fasting test and a computed tomography scan with contrast to localize the insulinoma. Multiple endocrine neoplasia type 1 is excluded due to other laboratory analyses – parathyroid hormones, the hormones of the hypophysis, ionized Calcium which are in the referent values. The patient was referred for surgery and the histopathological examination confirmed the diagnosis of insulinoma. Postoperative patient without symptoms, with glycaemia in reference values.

Conclusion: When we have a case of insulinoma we need to determine whether it is an isolated case or is part of multiple endocrine neoplasia type 1 (MEN 1). In the case of the patient we are treating we concluded that it is an isolated case of insulinoma.

Because 90 % of insulinomas are benign and long-term cure with a total resolution of preoperative symptoms is expected after complete resection.