Renal Cell Carcinoma and a Pancreatic Neuroendocrine Tumor: A Coincidence or Instance of Von Hippel-Lindau Disease?

We herein report a rare case of a 79-year-old man who presented with the simultaneous occurrence of pancreatic neuroendocrine tumors (PNET) and renal cell carcinomas (RCC), without any other Von Hippel-Lindau (VHL)-associated lesions or any pertinent family history. Computed tomography showed vascular-rich solid lesions in the left kidney and the pancreatic tail, measuring 72 mm and 15 mm in size, respectively. Preoperatively, RCC with pancreatic metastasis was suspected and laparotomy was performed. However, the resected specimens revealed a different tumor histology, namely renal clear cell carcinoma (G2, pT3) and PNET (G1, pT3). The patient and his family refused genetic testing, however, so far, the patient has not developed any VHL-associated lesions for more than four years.

Attainment of a Long-term Favorable Outcome by Sunitinib Treatment for Pancreatic Neuroendocrine Tumor and Renal Cell Carcinoma Associated with von Hippel-Lindau Disease.

von Hippel-Lindau (VHL) disease, caused by germline mutations in the VHL gene, is a hereditary autosomal-dominant disorder which predisposes the individual to various malignant and benign tumors. VHL acts as a tumor suppressor, mainly through the negative regulation of hypoxia-inducible factors. Molecular-targeted drugs against vascular endothelial growth factor-signaling pathways, a target of hypoxia-inducible factors, have recently been introduced into clinical practice for the treatment of patients with sporadic renal cell carcinoma and pancreatic neuroendocrine tumors. However, whether such treatments are effective in patients with VHL disease remains to be elucidated. We herein report a Japanese patient with VHL disease who was successfully treated with sunitinib for approximately 5 years.

Pancreatic endocrine tumour with disseminated pulmonary thromboembolism in an owl monkey (Aotus nancymae).

Pulmonary thromboembolism associated with pancreatic endocrine neoplasia is extremely uncommon in man and animals. Post-mortem examination of an adult owl monkey (Aotus nancymae) revealed extensive pulmonary arterial thromboembolism and a well-demarcated mass attached to the pancreas. Microscopically, the mass consisted of areas of interstitial fibrosis with loss of acini and islets and replacement by nests and sheets of polygonal cells with amphophilic cytoplasm, an eccentric round nucleus with stippled chromatin and, in some cells, with a single prominent eccentric nucleolus. Clusters of these cells were noted within vessels and adjacent lymph nodes. The cells did not express S100 or insulin, but were labelled strongly with SP-1/chromogranin. Rare individual cells expressed glucagon and somatostatin. A few cells in pulmonary thrombi/emboli and the adjacent lymph node also expressed SP-1/chromogranin. Based on cell morphology, location and immunohistochemistry the tumour was classified as pancreatic endocrine (islet cell) carcinoma with metastasis to regional lymph nodes and lung.

GLP-1 and glucagon secretion from a pancreatic neuroendocrine tumor causing diabetes and hyperinsulinemic hypoglycemia.

CONTEXT: Glucagon-like peptide-1 (GLP-1) is a gut peptide that promotes insulin release from pancreatic ß-cells and stimulates ß-cell hyperplasia. GLP-1 secretion causing hypoglycemia has been described once from an ovarian neuroendocrine tumor (NET) but has not been reported from a pancreatic NET (pNET). OBJECTIVE: A 56-yr-old male with a previous diagnosis of diabetes presented with fasting hypoglycemia and was found to have a metastatic pNET secreting glucagon. Neither the primary tumor nor metastases stained for insulin, whereas the resected normal pancreas showed histological evidence of islet cell hyperplasia. We provide evidence that GLP-1 secretion from the tumor was the cause of hyperinsulinemic hypoglycemia. METHODS: GLP-1 levels were determined in the patient, and immunohistochemistry for GLP-1 was performed on the tumor metastases. Ex vivo tissue culture and a bioassay constructed by transplantation of tumor into nude mice were performed to examine the tumor secretory products and their effects on islet cell function. RESULTS: The patient had high levels of glucagon and GLP-1 with an exaggerated GLP-1 response to oral glucose. Immunohistochemistry and primary tissue culture demonstrated secretion of glucagon and GLP-1 from the tumor metastases, whereas insulin secretion was almost undetectable. Ex vivo coculture of the tumor with normal human islets resulted in inhibition of insulin release, and transplanted mice developed impaired glucose tolerance. CONCLUSIONS: This is the first description of glucagon and GLP-1 secretion from a metastatic pNET causing sequential diabetes and hypoglycemia. Hypoglycemia was caused by insulin secretion from hyperplastic ß-cells stimulated by tumor-derived GLP-1.

[Insulinoma]. / Wyspiak wydzielajacy insuline.

Insulinoma is considered the most common endocrine tumour of the pancreas with an annual prevalence of 4 cases per million people. Contrary to the other endocrine tumours of this organ, over 90% of the insulinomas are benign in nature. The clinical presentation of this neoplasm depends on excessive production of insulin and pro-insulin and is characterised by the symptoms of neuroglycopenia and catecholamine response. Effective management requires directed biochemical testing, careful choice of preoperative imaging tests, and complete pancreatic exploration by an experienced endocrine surgeon utilising intraoperative ultrasound. The only curative treatment for insulinoma is complete resection of the tumour. The aim of this paper is to critically discuss contemporary diagnosis and treatment of this neoplasm on the basis of progress made in recent years.

Pancreatic carcinoma coexisting with chronic pancreatitis versus tumor-forming pancreatitis: diagnostic utility of the time-signal intensity curve from dynamic contrast-enhanced MR imaging.

AIM: To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially pancreatic carcinoma coexisting with chronic pancreatitis and tumor-forming pancreatitis. METHODS: Forty-eight consecutive patients who underwent surgery for a focal pancreatic mass, including pancreatic ductal carcinoma (n=33), tumor-forming pancreatitis (n=8), and islet cell tumor (n=7), were reviewed. Five pancreatic carcinomas coexisted with longstanding chronic pancreatitis. The pancreatic TICs were obtained from the pancreatic mass and the pancreatic parenchyma both proximal and distal to the mass lesion in each patient, prior to surgery, and were classified into 4 types according to the time to a peak: 25 s and 1, 2, and 3 min after the bolus injection of contrast material, namely, type-I, II, III, and IV, respectively, and were then compared to the corresponding histological pancreatic conditions. RESULTS: Pancreatic carcinomas demonstrated type-III (n=13) or IV (n=20) TIC. Tumor-forming pancreatitis showed type-II (n=5) or III (n=3) TIC. All islet cell tumors revealed type-I. The type-IV TIC was only recognized in pancreatic carcinoma, and the TIC of carcinoma always depicted the slowest rise to a peak among the 3 pancreatic TICs measured in each patient, even in patients with chronic pancreatitis. CONCLUSION: Pancreatic TIC from dynamic MRI provides reliable information for distinguishing pancreatic carcinoma from other pancreatic masses, and may enable us to avoid unnecessary pancreatic surgery and delays in making a correct diagnosis of pancreatic carcinoma, especially, in patients with longstanding chronic pancreatitis.

Multiple ectopic lesions of focal islet adenomatosis identified by positron emission tomography scan in an infant with congenital hyperinsulinism.

Congenital hyperinsulinism (HI) exists in 2 histologic forms, focal and diffuse, and rarely has been attributed to lesions in ectopic pancreatic tissue. The ability to distinguish focal from diffuse HI and locate focal lesions has been difficult, thus limiting the optimal management of HI. We present a case of HI resulting from focal pancreatic and ectopic pancreatic lesions. After a near-total pancreatectomy failed to improve the patient's condition, a positron emission tomography (PET) scan performed with 18F-fluoro-L-dihydroxyphenylalanine demonstrated a focal lesion remaining in the head of the pancreas as well as 4 hot spots inferior to the remaining pancreas. Surgical exploration found pancreatic rests in the jejunum responsible for the hot spots seen on PET. Resection of the remainder of the pancreas as well as the small intestinal lesions resulted in correction of the patient's HI. Pathology confirmed the presence of focal HI lesions in the pancreatic head and small intestinal specimens. This case supports the ability of ectopic pancreatic tissue to contribute to the pathology of HI. It highlights the ability of PET to successfully identify focal lesions, including ectopic tissue, responsible for hyperinsulinemic hypoglycemia.

Renal cell carcinoma with non-islet cell tumor hypoglycemia.

We report a case of an elderly gentleman with renal cell carcinoma presenting with the rare entity of non-islet cell tumor hypoglycemia (NICTH). Non-islet cell tumor hypoglycemia syndrome is caused by the tumor producing insulin-like growth factor II, causing hypoglycemia. The syndrome is most commonly associated with very large fibromas or fibrosarcomas.

Extensive acrochordons and pancreatic islet-cell tumors in tuberous sclerosis associated with TSC2 mutations.

Acrochordons are frequently encountered benign skin lesions that may occasionally represent underlying pathology. Pancreatic islet-cell tumors are rare neoplasms and few cases have been described in patients with tuberous sclerosis complex (TSC). A 39-year-old man presenting in acute renal failure was referred to us for further diagnostic evaluation of coincidentally noted dysmorphic features. Physical examination revealed over 1,000 acrochordons in addition to findings meeting criteria for TSC. The diagnosis was confirmed by disclosure of mutation in the TSC2 gene. Further evaluation revealed pancreatic islet cell tumors. Acrochordons are a common skin lesion, but when presenting in an atypical manner or unusual number may be a sign of TSC and underlying occult pathology thereby warranting evaluation of TSC2. Additionally, mutations in TSC2 gene may be a risk factor for developing pancreatic islet-cell tumors.

Gastrointestinal manifestations of endocrine disease.

The hormonal interactions among the systems throughout the body are not fully understood; many vague clinical symptoms may in fact be manifestations of underlying endocrine diseases. The aim of the following review is to discuss gastrointestinal manifestations of surgically correctable endocrine diseases, focusing on abnormalities of thyroid function, cancer and finally autoimmune diseases. We also review manifestations of pancreatic endocrine tumors, and multiple endocrine neoplasia.

Microadenomatosis of the endocrine pancreas in patients with and without the multiple endocrine neoplasia type 1 syndrome.

It has been suggested that microadenomatosis of the endocrine pancreas is a hallmark of the multiple endocrine neoplasia type 1 syndrome (MEN1). This study attempts to elucidate the relationship between pancreatic microadenomatosis and the MEN1 and von Hippel-Lindau (VHL) syndromes. Pancreatic tissue specimens from 37 patients (with either microadenomatosis or the MEN1 syndrome) were analyzed using immunohistochemistry, confocal laser scanning microscopy, and morphometric methods. The MEN1 and the VHL status were assessed on the basis of clinical criteria (all patients) and PCR-based mutational analysis (15 and 5 patients, respectively). Pancreatic microadenomatosis was found in 35 of 37 patients, 28 of whom fulfilled the clinicopathologic criteria and 13 the genetic criteria for MEN1, whereas none of the patients had evidence of a VHL syndrome. Microadenomas were present in 26 of the 28 MEN1 patients, and all these tumors were consistently multihormonal. Five of the 9 patients with microadenomatosis and no clinical evidence for MEN1 or VHL also lacked mutations for the respective genes. Five of these 9 patients suffered from hyperinsulinism and revealed multiple insulin-positive tumors. The other patients were nonsymptomatic and showed multiple glucagon-expressing neoplasms. In microadenomatosis patients with and without the MEN1 syndrome, a subset of morphologically normal-appearing islets showed increased endocrine cell proliferation. In conclusion, endocrine multihormonal microadenomatosis of the pancreas is a feature of MEN1. In addition, a monohormonal type of pancreatic microadenomatosis was identified that consisted of either insulinomas or glucagon-producing tumors and was not associated with MEN1 or VHL.

The diagnosis of fasting hypoglycemia due to an islet-cell tumor obscured by a highly specific insulin assay.

The work-up of fasting hypoglycemia may be difficult but is crucially important because a wrong diagnosis can lead to either unnecessary pancreatectomy or a missed pancreatic tumor. We describe a patient with severe fasting hypoglycemia [22-32 mg/dl (1.2-1.8 mmol/liter) after 6-10 h of fasting] in which the diagnosis of a secretory islet-cell tumor was obscured, rather than facilitated, by use of a new, highly specific serum insulin assay. Insulin measured by the specific assay suppressed normally during fasting hypoglycemia [undetectable at < 2.0-3.8 micro IU/ml (26.4 pmol/liter)], whereas insulin measured by older, less specific assays was diagnostically elevated [34, 73 micro IU/ml (236.1, 507.0 pmol/liter)]. Serum proinsulin and C-peptide levels were abnormal, and further work-up revealed an islet-cell tumor that secreted predominantly proinsulin. The tumor was surgically removed, relieving the fasting hypoglycemia. We conclude that insulin levels as measured by new, highly specific insulin assays may obscure the diagnosis of a functional, proinsulin-secreting islet-cell tumor. Because proinsulin cross-reacts with insulin in older insulin assays, C-peptide or proinsulin should be measured to rule out a proinsulin-secreting islet-cell tumor. Normative values for new insulin assays must be established during prolonged fasting.

Uncontrolled insulin secretion from a childhood pancreatic beta-cell adenoma is not due to the functional loss of ATP-sensitive potassium channels.

We report the case of an 8-year-old child who presented with severe hyperinsulinaemic hypoglycaemia due to a pancreatic islet cell adenoma. In vivo, there was no beneficial response to the hyperglycaemia-inducing agent diazoxide and as a consequence the child underwent a subtotal pancreatectomy. In vitro studies of adenomatous beta-cells revealed no operational defects in ATP-sensitive potassium channel activity and appropriate responses to diazoxide. In comparison with patients with focal adenomatous hyperplasia, genetic analysis of the isolated adenoma showed no loss of heterozygosity for chromosome 11p15 and expression of the cyclin-dependent kinase inhibitor p57(kip2). This case illustrates that the excess insulin secretion from an infantile adenoma has an aetiology different from that observed in hyperinsulinism in infancy.