Assessment of suspected insulinoma by 48-hour fasting test: a retrospective monocentric study of 23 cases.

OBJECTIVE: Insulinoma causes fasting hypoglycaemia due to inappropriate insulin secretion. The diagnosis of insulinoma is based on Whipple's triad during a supervised fasting test. The aim of our study was to evaluate retrospectively the percentage of positive 48-hour fasting tests in a large series of patients with insulinoma. DESIGN, PATIENTS AND METHODS: In a retrospective study, we identified 39 patients (24 females, 15 men; average age 47 years [range 12-78 years]) with insulinoma. Sixteen patients were diagnosed by spontaneous hypoglycaemia. Twenty-three patients with insulinoma were tested with a 48-hour fasting test and compared to 31 healthy controls who had a negative fasting test and were followed up for at least two years. RESULTS: The fast was terminated due to neuroglycopenic symptoms in 4 patients (17.4%) at the 12th hour, in 17 patients (73.9%) at the 24th hour, and in 22 patients (95.7%) at the 48th hour. One patient with insulinoma had no neuroglycopenic symptoms, but was diagnosed by glucose and insulin levels during the 48-hour fast. Healthy controls had significantly higher blood glucose and lower insulin levels, and a lower insulin-glucose ratio than patients with insulinoma at the end of the fast. CONCLUSIONS: In conclusion, the 48-hour fasting test was successful in the diagnosis of insulinoma in 95.7% of patients. In this series we did not observe a need for fasting beyond 48 hours.

Elevated transaminases during medical treatment of acromegaly: a review of the German pegvisomant surveillance experience and a report of a patient with histologically proven chronic mild active hepatitis.

OBJECTIVE: The new GH receptor antagonist pegvisomant is the most effective medical therapy to normalize IGF-I levels in patients with acromegaly. Based on currently available data pegvisomant is well tolerated; however, treatment-induced elevation of transaminases has been reported and led to the necessity for drug discontinuation in some patients in the pivotal studies. The aim of this study was to evaluate and characterize the prevalence of elevated transaminases and to describe in detail the findings in a single case who required drug discontinuation because of elevation of transaminases which emerged during treatment and who underwent liver biopsy. DESIGN AND METHODS: Retrospective safety analyses were carried out on 142 patients with acromegaly receiving pegvisomant treatment in Germany between March 2003 and the end of 2004. Of these patients, 123 were documented in a post-marketing surveillance study, one case of elevated transaminases was reported spontaneously and the other patients were treated in a clinical study. RESULTS: Mean treatment duration with pegvisomant in the ongoing observational study at the end of 2004 was 28.3 +/- 19.9 (S.D.) weeks. Twelve out of the 142 patients had elevated transaminases above three times the upper limit of normal, likely caused by biliary obstruction in five of the patients. All patients but one affected by elevated transaminases had been previously treated with somatostatin analogues. In six out of 142 (4%) of patients, pegvisomant was permanently withdrawn because of elevated transaminases. The same number of patients showed a transient increase of transaminases with either spontaneous remission without dose modification (n = 4) or no re-increase of transaminases after temporary discontinuation and re-exposure (n = 2). The liver biopsy of one patient who was permanently withdrawn showed a chronic mild hepatitis with a mixed portal inflammation including eosinophilic granulocytes. CONCLUSIONS: Liver function tests should be regularly followed on pegvisomant treatment. Biliary complications, which may arise from restitution of normal gall bladder motility after cessation of somatostatin analogue treatment, need to be differentiated from pegvisomant-induced abnormalities. The histological pattern of the liver biopsy performed in one of the patients showed a mild chronic active hepatitis. The lack of dose dependency and rather low frequency of elevated transaminases in those cases where a biliary disorder was excluded render this reaction an idiosyncratic drug toxicity.

[Autoimmune hypophysitis--two case reports]. / Autoimmunhypophysitis -- Zwei Fallberichte.

HISTORY AND CLINICAL FINDINGS: Two young female patients presented with polyuria and polydipsia. In one patient we additionally found idiopathic vitiligo, there were no relevant previous diseases. The gynaecological history was unremarkable. INVESTIGATIONS: In both cases a water deprivation test confirmed the diagnosis of central diabetes insipidus, the MRI investigation of the pituitary region showed a prominent and thickened pituitary stalk. DIAGNOSIS: After exclusion of a systemic granulomatous inflammation we diagnosed an autoimmune hypophysitis based on the typical morphological lesions of the pituitary gland and stalk. TREATMENT AND FOLLOW-UP: High-dose glucocorticoid therapy was without any beneficial effect on the central diabetes insipidus. Desmopressin treatment was initiated and led to a normalization of the pre-existing polyuria and polydipsia. CONCLUSION: Autoimmune hypophysitis is a very rare disease and the diagnosis is mostly achieved by excluding other causes. Systematic evaluations on large patient cohorts are lacking in the literature with respect to diagnostic procedures, therapy and outcome, the existing knowledge and experience is largely based on case reports. For this reason it appears desirable to create a central register to collect and to evaluate the course of disease in patients with autoimmune hypophysitis.

Primary neuroendocrine carcinoma of inguinal lymph node.

Ninety-seven percent of neuroendocrine carcinomas are located in the gastrointestinal tract or in the bronchopulmonary tree. Inguinal lymph nodes as the primary tumor site for neuroendocrine carcinoma represent a very unusual location, and have only been described in 2 patient series in the literature. A 64-year-old, previously healthy, Caucasian female presented with a 2-month history of an enlarged inguinal lymph node on the right side. The removed lymph node showed histological and immunohistochemical characteristics of neuroendocrine differentiation (positive for synaptophysin, cytokeratin 20, neuron-specific enolase and chromogranin A). Although extensive investigations including repeated CT and NMR scans, classical endoscopy, wireless capsule endoscopy of the small intestine, octreotide- and MIBG scintigraphy were performed, no other primary tumor was found. Furthermore, there was no evidence of Merkel cell carcinoma on dermatological examinations. A possible explanation for the presence of neuroendocrine carcinomas within the lymph nodes is malignant transformation of preexisting intranodal epithelial nests, which have previously been described in lymph nodes located close to the salivary glands, thyroid gland, breast tissue and pancreas. Since the surgical removal of the affected lymph node, the patient has now been disease-free for 42 months. We therefore consider our case to represent a primary undifferentiated neuroendocrine carcinoma in an inguinal lymph node.

Improved assessment of body cell mass by segmental bioimpedance analysis in malnourished subjects and acromegaly.

BACKGROUND: Estimation of body cell mass (BCM) has been regarded valuable for the assessment of malnutrition. AIM: To investigate the value of segmental bioelectrical impedance analysis (BIA) for BCM estimation in malnourished subjects and acromegaly. METHODS: Nineteen controls and 63 patients with either reduced (liver cirrhosis without and with ascites, Cushing's disease) or increased BCM (acromegaly) were included. Whole-body and segmental BIA (separately measuring arm, trunk, leg) at 50 kHz was compared with BCM measured by total-body potassium. Multiple regression analysis was used to develop specific equations for BCM in each subgroup. RESULTS: Compared to whole-body BIA equations, the inclusion of arm resistance improved the specific equation in cirrhotic patients without ascites and in Cushing's disease resulting in excellent prediction of BCM (R(2) = 0.93 and 0.92, respectively; both P<0.001). In acromegaly, inclusion of resistance and reactance of the trunk best described BCM (R(2) = 0.94, P<0.001). In controls and in cirrhotic patients with ascites, segmental impedance parameters did not improve BCM prediction (best values obtained by whole-body measurements: R(2)=0.88 and 0.60; P<0.001 and <0.003, respectively). CONCLUSION: Segmental BIA improves the assessment of BCM in malnourished patients and acromegaly, but not in patients with severe fluid overload.

[Prevalence of diabetes in acromegaly and Cushing syndrome]. / Diabetes-Häufigkeit bei Akromegalie und Cushing-Syndrom.

In a retrospective study glucose metabolism was investigated in 206 patients with acromegaly and 131 patients with Cushing's disease. 40.5% of the patients with hypersomatotropism and 32.0% of the patients with hypercortisolism suffered from overt diabetes mellitus. Impaired glucose tolerance was present prior to therapy in 28.2% and 30.6% of the patients, respectively. In acromegaly the incidence of overt diabetes mellitus was higher in women than in men, but no difference existed in the distribution of impaired glucose tolerance between both sexes. No correlation was found between growth hormone levels and occurrence of diabetes. In acromegaly and Cushing's disease overt diabetes increased with advanced age. Diabetes mellitus occurred independently from the etiology of hypercortisolism.

[Food-dependent Cushing syndrome of long standing with mild clinical features]. / Nahrungsabhängiges Cushing-Syndrom mit langer Anamnese und moderater Klinik.

HISTORY AND CLINICAL FINDINGS: A 40-year-old woman complained of weight gain for 10 years. Because of this, she yearly went on a excessive weight reduction diet with weight loss of up to 12 kg. Nevertheless, a total weight gain of 15 kg as well as changing degrees of hypertension, muscular weakness and severe depression were registered during this long period. For 5 years ecchymosis and for 2 years oligomenorrhoea as well as oedema had become evident. Recently large macronodular adrenal glands were found on routine abdominal ultrasound. At the time of clinical investigation early this year she presented with relatively mild Cushing features, such as moon face, central obesity, hirsutism, ecchymosis and hypertension. INVESTIGATIONS: Endocrine testing demonstrated suppressed plasma ACTH, low to normal plasma cortisol after overnight fasting and an inverse diurnal rhythm. During 24 hours of fasting plasma cortisol levels and free urinary cortisol excretion were within normal range, but highly elevated under normal food intake. Plasma cortisol levels increased dramatically in response to a lipid-rich meal (5.6-fold), to a protein-rich meal (6.6-fold) and to oral glucose (3.7-fold). Increases in plasma cortisol were closely correlated to increases of gastric inhibitory polypeptide (GIP) concentrations. Subcutaneous injection of octreotide completely inhibited the plasma cortisol and GIP response to oral glucose. Plasma ACTH and cortisol levels did not increase after CRH administration, but fasting plasma cortisol promptly increased after ACTH stimulation. Non-fasting plasma cortisol levels and free urinary cortisol excretion were not suppressed by high doses of dexamethasone. Abdominal computed tomography showed macronodular enlargement of both adrenal glands. TREATMENT AND COURSE: The patient underwent bilateral adrenalectomy. Postoperatively, she was treated with replacement doses of hydrocortisone and fludrocortisone. All Cushing features have regressed, a normal menstrual cycle and normal plasma ACTH concentrations have become evident. CONCLUSION: This case report not only presents a very rare cause of Cushing's syndrome--food-dependent or gastric inhibitory peptide (GIP)-dependent hypercortisolism--but it also demonstrates a special course of this disease of relatively long duration. Severe adrenal hyperplasia contrasted with mild clinical symptoms obviously caused by frequent periods of weight reduction diet. Considering this moderate clinical course it might well be that food-dependent hypercortisolism is more frequent than supposed, but not diagnosed owing to relatively mild clinical symptoms.