Clinicopathological characteristics and non-adhesive organ culture of insulinomas.

BACKGROUND AND AIMS: Insulinoma is a very rare type of islet cell tumour, but nevertheless the most common endocrine tumour of the pancreas. We aimed at reviewing our clinical experience with this tumour type and to assess whether organ culture could be obtained from surgically resected insulinoma material. MATERIAL AND METHODS: All patients with insulinomas (6 men and 10 women) referred to Haukeland University Hospital between 1986 and 2006 were included in the study. Median age of onset was 53 years (range 21-74). Biochemical diagnosis was established during a 72 h fast test. Imaging and localization of the tumours were performed with intra-operative ultrasonography, endoscopic ultrasonography, CT-scan and/or transcutaneous ultrasonography. For six patients, organ cultures were set up from tumour tissue fragments. RESULTS: The annual incidence of insulinoma was 0.8 per million. The patients generally presented with non-specific, episodic symptoms, which often were mistaken for cardiovascular, neurological or diabetic disease and in some cases delayed the diagnosis with several years. Two patients had diabetes prior to the diagnosis of insulinoma. Patient weight gain was probably due to increased food intake, compensating for the hypoglycemia. Intra-operative ultrasonography detected all tumours correctly, whereas 73% were detected by endoscopic ultrasonography and 38% by CT scan. Five insulinomas were located in the head, eight in the body and three in the tail of the pancreas. All were removed by open-access surgery, eleven cases by resection and five by enucleation. One tumour was malignant with liver metastases and two patients had tumours defined as borderline. Insulinoma tissue fragments developed into spheroids during the first week of culturing and insulin secretion into the media was demonstrated. CONCLUSIONS: Insulinomas are rare and diagnostically challenging tumours. Intra-operative ultrasonography was superior to other imaging modalities to locate the lesion. In organ culture, insulinomas readily form spheroids which may be used to yield insight into beta-cell biology.

Saliva cortisol measurement: simple and reliable assessment of the glucocorticoid replacement therapy in Addison's disease.

No ideal parameter is available for assessment of the glucocorticoid replacement therapy in Addison's disease. Serum cortisol day-curves can be used to monitor the therapy, but this technique is cumbersome and expensive. We evaluated the potential for saliva cortisol measurement in this setting. We found excellent correlation between serum and saliva cortisol after oral intake of cortisone acetate (no. 7) or iv administration of hydrocortisone (no. 4) (Pearson's R=0.83-0.98, p<0.002). A morning dose of 12.5 mg cortisone acetate yielded wide interindividual variations in cortisol levels in saliva. Saliva cortisol measurements were successfully adopted to evaluate and adjust doses in outpatients. We conclude that cortisol measurement in saliva is practical and reliable, and is preferable to serum cortisol measurement in the assessment of the glucocorticoid replacement therapy. Our results confirm that only a minority of patients require more than 12.5 mg of cortisone acetate (equivalent to 10 mg hydrocortisone) in the morning to have sufficient cortisol levels during the first part of the day.