Justin Ging-Shing Won

The Role of Intra-Arterial Calcium Stimulation Test with Hepatic Venous Sampling (IACS) in the Management of Occult Insulinomas

BackgroundOccult insulinomas remain a clinical challenge. Specifically designed protocols are necessary to aid detection and facilitate a focused pancreatic exploration.MethodsSeventeen non-multiple endocrine neoplasia (non-MEN) patients referred to this medical center in the past 10 years because of equivocal diagnosis, failure of previous operation or difficulty in localization for insulinomas were studied. A routine intra-arterial calcium stimulation test with venous sampling (IACS test) was done for lesion localization. An exploratory laparotomy with intraoperative ultrasound (IOUS) examinations was performed.ResultsPreoperative imaging (sonography, high-resolution computed tomography scan, and magnetic resonance imaging) found six insulinomas, and IOUS found an additional six in the pancreatic regions; all were compatibly indicated by the IACS test. The remaining five patients with occult lesions by IOUS were treated by 40% (1) or 60–70% (4) distal pancreatectomies when insulin gradients were demonstrated on calcium stimulation to the splenic or to the superior mesenteric artery, respectively, and nesidioblastosis was found in each pathology examination. There were no complications related to the arterial stimulation and venous sampling (ASVS) test. No patient had recurrent hyperinsulinism, permanent morbidity, or mortality from surgery.ConclusionsIACS test helps in the diagnosis of equivocal pancreatogenous hypoglycemia, indicating the pancreatic region of priority exploration and guiding a pancreatic resection.

Primary hypothalamic lymphoma with panhypopituitarism presenting as stiff-man syndrome.

We report an unusual case of primary hypothalamic lymphoma with hypopituitarism presenting as Stiff-man syndrome (SMS). A 64-year-old man was hospitalized due to a 3-week history of general weakness, anorexia, vomiting, weight loss, and muscle pain and spasms precipitated by motion and tactile stimuli resulting in muscle stiffness and difficulty in mobility. Physical examination revealed normal sensorimotor function and reflexes, except for bitemporal visual field defect. Routine laboratory and gastrointestinal examinations provided no remarkable clues. Endocrine assessment revealed low levels of morning cortisol, thyroxine, and anterior pituitary hormones but an increase in prolactin level. The patient’s muscle pain and stiffness improved dramatically within 2 days after hydrocortisone therapy and thyroxine replacement. Magnetic resonance imaging (MRI) of the brain confirmed an 18-mm enhancing hypothalamic tumor with optic chiasm involvement, which proved to be a B-cell lymphoma. The results of the extensive studies for systemic lymphoma were negative, suggesting a primary hypothalamic lymphoma. The tumor regressed completely and was invisible on MRI scan after adjuvant radiotherapy. The patient’s condition was satisfactory and there was no recurrence of SMS during the 2-year follow-up period. This case demonstrated that primary hypothalamic lymphoma complicated with adrenal insufficiency may manifest as SMS. Early diagnosis and prompt intervention can lead to a favorable outcome and reduce morbidity.

Severe Hypoglycemic Coma due to Insulin Autoimmune Syndrome

Insulin autoimmune syndrome, characterized by the presence of insulin-binding autoantibodies and fasting or late postprandial hypoglycemia, is a rare cause of hypoglycemia. We report a patient with pulmonary tuberculosis who developed recurrent spontaneously post-absorptive hyperinsulinemic hypoglycemia after treatment with anti-tuberculous drugs. Imaging studies of the pancreas were unremarkable, and selective intra-arterial calcium stimulation with hepatic venous sampling for insulin failed to show a gradient, thus almost completely excluding the possibility of occult insulinoma or nesidioblastosis. Examinations of sera, however, disclosed a high titer of polyclonal insulin-binding autoantibodies containing at least 2 classes of binding sites, 1 with high affinity but low capacity, and the other with low affinity but high capacity. An oral glucose tolerance test revealed high serum levels of total insulin associated with relatively low levels of free insulin, but not of C-peptide, suggesting binding of the released insulin to autoantibodies. Regretfully, shortly after the withdrawal of isoniazid, the patient died of respiratory failure unrelated to hypoglycemia, and whether these antibodies were induced by isoniazid remains unknown. We recommend that insulin autoimmune syndrome be one of the differential diagnoses in patients with hyperinsulinemic hypoglycemia.

Assessment of Bilateral Inferior Petrosal Sinus Sampling (BIPSS) in the Diagnosis of Cushing's Disease

Background: The differential diagnosis of adrenocorticotropin (ACTH)‐dependent Cushings syndrome (CS) remains a challenging issue for clinical endocrinologists. In this respect, bilateral inferior petrosal sinus sampling (BIPSS) appears to be the most sensitive and specific test. Here, we report our 15‐year experience of analyzing the performance of BIPSS, both in the correct diagnosis and in the precise lateralization of tumors in patients with Cushings disease (CD). Methods: Between 1992 and 2006, 18 patients with CD (16 females, 2 males; age range, 14‐56 years) were admitted to Taipei Veterans General Hospital and subjected to BIPSS plus ovine corticotropin‐releasing hormone (oCRH) stimulation. Four of them had previously undergone transsphenoidal hypophysectomy (TSH) and had a recurrence thereafter. BIPSS was performed by inserting a catheter in the right and left inferior petrosal sinus for ACTH assay via a femoral vein puncture. An inferior petrosal sinus/peripheral ACTH ratio (C/P ratio) = 2 at baseline or = 3 after oCRH injection indicated a pituitary origin of ACTH secretion, and an interpetrosal ACTH gradient (IPS ratio) = 1.4 at baseline or after oCRH indicated evidence of lateralization. Results: Positive BIPSS results were found in 16 patients at baseline and in 17 patients after oCRH injection. In 17 out of 18 patients, TSH was subsequently carried out and a pituitary source was confirmed on histopathologic examination. The only 1 false‐negative test result was noted in a patient who had undergone previous TSH. Thus, the sensitivities of BIPSS for the diagnosis of CD before and after oCRH stimulation were 89% and 94%, respectively. Moreover, using an IPS ratio = 1.4 as a criterion, BIPSS correctly lateralized the tumor in 9 of 17 and 10 of 17 patients at baseline and after oCRH stimulation, respectively, including in 2 patients who had a centrally located tumor and who had an IPS ratio < 1.4. Thus, the sensitivities of lateralization of BIPSS were 53% and 59%, respectively. None of the 4 patients who had previous TSH were precisely localized by BIPSS. If these 4 patients were excluded, the sensitivities of BIPSS for localizing in the patients who had not undergone previous operation increased to 70% (9/13) at baseline and 77% (10/13) after oCRH stimulation, respectively. Conclusion: BIPSS combined with oCRH stimulation is a safe and reliable examination both in the differential diagnosis of CD and in the correct lateralization of pituitary microadenoma in patients without previous pituitary surgery. Nevertheless, this procedure may provide misleading results in patients who have received previous pituitary surgery.

Plasma corticotrophin response to desmopressin in patients with Cushing's disease correlates with the expression of vasopressin receptor 2, but not with that of vasopressin receptor 1 or 3, in their pituitary tumours

Objectivesu2002 Most patients with Cushing’s disease (CD) respond to corticotrophin‐releasing hormone (CRH) or desmopressin with increased corticotrophin (ACTH) and cortisol levels. Although the vasopressin receptor subtype located on normal corticotrophs is the V3 receptor (V3R), desmopressin is a selective V2 receptor (V2R) agonist and it is unclear whether corticotrophinomas exhibit aberrant V2R expression. Furthermore, no studies have determined the relationship between the in vivo response of CD patients to desmopressin and vasopressin receptor expression, or between the response to CRH and CRH receptor (CRHR) expression. Therefore, the aim of this study was to investigate the expression of vasopressin receptors (V1R, V2R, and V3R) and CRHR on corticotroph tumours and its possible relation to the in vivo response.

Adrenocortical carcinoma initially presenting with hypokalemia and hypertension mimicking hyperaldosteronism: a case report

BackgroundAdrenocortical carcinoma is a rare malignancy and rare cause of Cushing’s syndrome.Case presentationA 65-year-old seemingly well male patient was referred to our clinic under the suspicion of hyperaldosteronism due to hypertension combined with hypokalemia. However, his serum aldosterone and plasma renin activity were within normal limits. Instead, Cushing’s syndrome was diagnosed by elevated urine free cortisol and a non-suppressible dexamethasone test. Abdominal computed tomography showed a 7.8u2009×u20094.8xa0cm mass lesion at the right adrenal gland with liver invasion. Etomidate infusion was performed to reduce his cortisol level before the patient received a right adrenalectomy and liver wedge resection. The pathology report showed adrenocortical carcinoma with liver and lymph node metastasis. According to the European Network for the Study of Adrenal Tumors (ENSAT) staging system, the tumor was classified as T4N1M1, stage IV. Recurrent hypercortisolism was found shortly after surgery. The patient died of Fournier’s gangrene with septic shock on the 59th day after diagnosis.ConclusionsWe report a case of rapidly progressive stage IV adrenocortical carcinoma with initial presentations of hypokaelmia and hypertension, mimicking hyperaldosteronism.

The Ankle Brachial Index Exhibits Better Association of Cardiovascular Prognosis Than Non-High-Density Lipoprotein Cholesterol in Type 2 Diabetes

Objective: The association between ankle brachial index (ABI) and outcomes in diabetic subjects is controversial. The purpose of this study was to evaluate whether the ABI is more strongly associated with cardiovascular outcomes comparing with non–high‐density lipoprotein cholesterol (non–HDL‐c). Research Design and Methods: A total of 452 type 2 diabetic subjects followed up for a mean of 5.8 years were grouped by ABI (<0.9 versus ≥0.9) and non–HDL‐c (<100 mg/dL versus ≥100 mg/dL). Primary outcomes were composite events including all‐cause mortality, hospitalization for coronary artery disease, stroke, revascularization, amputation and diabetic foot, and the secondary end point was all‐cause mortality. Results: Intergroup differences in percentage of men, duration of diabetes, hemoglobin A1c, total cholesterol, low‐density lipoprotein cholesterol, triglycerides and estimated glomerular filtration rate were significant. A total of 64 composite events and 17 deaths were recorded. A higher number of composite events occurred in the group with abnormal ABI but optimal non–HDL‐c than in those with suboptimal non–HDL‐c but normal ABI (29% versus 11%, P < 0.05). A similar trend was observed in all‐cause mortality (11% versus 1%, P < 0.05). The ABI was the dominant risk factor for both end points after adjusting other factors (for composite events, hazard ratio = 0.02, 95% CI: 0.00‐0.10, P < 0.001 and for all‐cause mortality, hazard ratio = 0.01, 95% CI: 0.00‐0.28, P = 0.006). Conclusions: The ABI was more strongly associated with outcomes in diabetes than non–HDL‐c. The ABI should be routinely screened in diabetes even without symptom.

A case of adrenal Cushing’s syndrome with bilateral adrenal masses

Summary A functional lesion in corticotrophin (ACTH)-independent Cushing’s syndrome is difficult to distinguish from lesions of bilateral adrenal masses. Methods for distinguishing these lesions include adrenal venous sampling and 131I-6β-iodomethyl-19-norcholesterol (131I-NP-59) scintigraphy. We present a case of a 29-year-old Han Chinese female patient with a history of hypercholesterolaemia and polycystic ovary syndrome. She presented with a 6month history of an 8kg body weight gain and gradual rounding of the face. Serial examinations revealed loss of circadian rhythm of cortisol, elevated urinary free-cortisol level and undetectable ACTH level (<5pg/mL). No suppression was observed in both the low- and high-dose dexamethasone suppression tests. Adrenal computed tomography revealed bilateral adrenal masses. Adrenal venous sampling was performed, and the right-to-left lateralisation ratio was 14.29. The finding from adrenal scintigraphy with NP-59 was consistent with right adrenal adenoma. The patient underwent laparoscopic right adrenalectomy, and the pathology report showed adrenocortical adenoma. Her postoperative cortisol level was 3.2μg/dL, and her Cushingoid appearance improved. In sum, both adrenal venous sampling and 131I-NP-59 scintigraphy are good diagnostic methods for Cushing’s syndrome presenting with bilateral adrenal masses. Learning points The clinical presentation of Cushing’ syndrome includes symptoms and signs of fat redistribution and protein-wasting features. The diagnosis of patients with ACTH-independent Cushing’s syndrome with bilateral adrenal masses is challenging for localisation of the lesion. Both adrenal venous sampling and 131I-NP-59 scintigraphy are good methods to use in these patients with Cushing’s syndrome presenting with bilateral adrenal masses.

The ankle brachial index is associated with prognosis in patients with diabetic kidney disease.

AIMSnPeripheral arterial disease (PAD) could be an additional risk factor for the clinical outcomes in different populations. The purpose of this study was to evaluate the influence of PAD on patients with diabetic kidney disease.nnnMETHODSn362 persons with type 2 diabetes were followed-up for a mean 4.8 years grouped by ankle brachial index (ABI) (<0.9 vs. ≧0.9) and albuminuria (with or without). Primary and secondary outcomes were composite events (all-cause mortality, hospitalization for coronary artery disease, stroke, re-vascularization, amputation, and diabetic foot) and all-cause mortality.nnnRESULTSnInter-group differences in duration of diabetes, glycated hemoglobin, creatinine, and estimated glomerular filtration rate were significant. During the follow-up period, 53 composite events were recorded (14.7%) and 13 (3.5%) individuals died. Subjects with albuminuria plus ABI<0.9 had higher risk of composite events than those with albuminuria but normal ABI (p<0.05). The only trend difference between the two groups was in all-cause mortality. Albuminuria plus ABI <0.9 was associated with risk of composite events (hazard ratio [HR] 4.20, 95% confidence interval [CI] 1.77-9.92, p=0.001) and all-cause mortality (HR 17.77, 95% CI 1.93-162.20, p=0.011).nnnCONCLUSIONSnPAD might be an additional risk factor for adverse outcomes in patients with diabetic kidney disease. Further prospective data are required to validate this conclusion.

Unusual Visualization of an Adrenal Carcinoma on NP-59 Scintiscan

[Iodine-131]6-beta-iodomethylnorcholesterol (NP-59) visualization of adrenocortical carcinoma is unusual. We describe a 17-year-old female with virilization and elevated plasma testosterone, dehydroepiandrosterone sulfate (DHEAS) and aldosterone. Magnetic resonance imaging disclosed a 9-cm right adrenal mass. NP-59 adrenal scanning displayed unilateral uptake of tracer and no visualization of the contralateral adrenal gland. Exploratory laparotomy revealed adrenocortical carcinoma. Subsequent immunohistochemical studies confirmed that the tumor was capable of producing a mixture of steroids, including testosterone, DHEAS and aldosterone. Visualization of an adrenal tumor on NP-59 scintiscan is an unusual finding, which cannot exclude the possibility of malignancy.