Cytology of islet tumours and hyperplasias associated with the Zollinger-Ellison syndrome

Diffuse, Adult-Onset Nesidioblastosis/Non-Insulinoma Pancreatogenous Hypoglycemia Syndrome (NIPHS): Review of the Literature of a Rare Cause of Hyperinsulinemic Hypoglycemia

Differential diagnosis of hypoglycemia in the non-diabetic adult patient is complex and comprises various diseases, including endogenous hyperinsulinism caused by functional β-cell disorders. The latter is also designated as nesidioblastosis or non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS). Clinically, this rare disease presents with unspecific adrenergic and neuroglycopenic symptoms and is, therefore, often overlooked. A combination of careful clinical assessment, oral glucose tolerance testing, 72 h fasting, sectional and functional imaging, and invasive insulin measurements can lead to the correct diagnosis. Due to a lack of a pathophysiological understanding of the condition, conservative treatment options are limited and mostly ineffective. Therefore, nearly all patients currently undergo surgical resection of parts or the entire pancreas. Consequently, apart from faster diagnosis, more elaborate and less invasive treatment options are needed to relieve the patients from the dangerous and devastating symptoms. Based on a case of a 23-year-old man presenting with this disease in our department, we performed an extensive review of the medical literature dealing with this condition and herein presented a comprehensive discussion of this interesting disease, including all aspects from epidemiology to therapy.

Zollinger-Ellison syndrome. Clinical presentation in 261 patients

We prospectively evaluated the initial presenting symptoms in 261 patients with Zollinger-Ellison syndrome (ZES) over a 25-year period. Twenty-two percent of the patients had multiple endocrine neoplasia-type 1 (MEN-1) with ZES. Mean age at onset was 41.1 +/- 0.7 years, with MEN-1 patients presenting at a younger age than those with sporadic ZES (p < 0.0001). Three percent of the patients had onset of the disease < age 20 years, and 7% > 60 years. A mean delay to diagnosis of 5.2 +/- 0.4 years occurred in all patients. A shorter duration of symptoms was noted in female patients and in patients with liver metastases. Abdominal pain and diarrhea were the most common symptoms, present in 75% and 73% of patients, respectively. Heartburn and weight loss, which were uncommonly reported in early series, were present in 44% and 17% of patients, respectively. Gastrointestinal bleeding was the initial presentation in a quarter of the patients. Patients rarely presented with only 1 symptom (11%); pain and diarrhea was the most frequent combination, occurring in 55% of patients. An important presenting sign that should suggest ZES is prominent gastric body folds, which were noted on endoscopy in 94% of patients; however, esophageal stricture and duodenal or pyloric scarring, reported in numerous case reports, were noted in only 4%-10%. Patients with MEN-1 presented less frequently with pain and bleeding and more frequently with nephrolithiasis. Comparing the clinical presentation before the introduction of histamine H2-receptor antagonists (pre-1980, n = 36), after the introduction of histamine H2-receptor antagonists (1981-1989, n = 118), and after the introduction of proton pump inhibitors (PPIs) (> 1990, n = 106) demonstrates no change in age of onset; delay in diagnosis; frequency of pain, diarrhea, weight loss; or frequency of complications of severe peptic disease (bleeding, perforations, esophageal strictures, pyloric scarring). Since the introduction of histamine H2-receptor antagonists, fewer patients had a previous history of gastric acid-reducing surgery or total gastrectomy. Only 1 patient evaluated after 1980 had a total gastrectomy, and this was done in 1977. The location of the primary tumor in general had a minimal effect on the clinical presentation, causing no effect on the age at presentation, delay in diagnosis, frequency of nephrolithiasis, or severity of disease (strictures, perforations, peptic ulcers, pyloric scarring). Disease extent had a minimal effect on symptoms, with only bleeding being more frequent in patients with localized disease. Patients with advanced disease presented at a later age and with a shorter disease history (p = 0.001), were less likely to have MEN-1 (p = 0.0087), and tended to have diarrhea more frequently (p = 0.079). A correct diagnosis of ZES was made by the referring physician initially in only 3% of the patients. The most common misdiagnosis made were idiopathic peptic ulcer disease (71%), idiopathic gastroesophageal reflux disease (GERD) (7%), and chronic idiopathic diarrhea (7%). Other less common misdiagnosis were Crohn disease (2%) and various diarrhea diseases (celiac sprue [3%], irritable bowel syndrome [3%], infectious diarrhea [2%], and lactose intolerance [1%]). Other medical disorders were present in 55% of all patients; patients with sporadic disease had fewer other medical disorders than patients with MEN-1 (45% versus 90%, p < 0.00001). Hyperparathyroidism and a previous history of kidney stones were significantly more frequent in patients with MEN-1 than in those with sporadic ZES. Pulmonary disorders and other malignancies were also more common in patients with MEN-1. These results demonstrate that abdominal pain, diarrhea, and heartburn are the most common presenting symptoms in ZES and that heartburn and diarrhea are more common than previously reported. The presence of weight loss especially with abdominal pain, diarrhea, or heartburn is an important clue suggesting the presence of gastrinoma. The presence of prominent gastric body folds, a clinical sign that has not been appreciated, is another important clue to the diagnosis of ZES. Patients with MEN-1 presented at an earlier age; however, in general, the initial symptoms were similar to patients without MEN-1. Gastrinoma extent and location have minimal effects on the clinical presentation. Overall, neither the introduction of successful antisecretory therapy nor widespread publication about ZES, attempting to increase awareness, has shortened the delay in diagnosis or reduced the incidence of patients presenting with peptic complications. The introduction of successful antisecretory therapy, however, has dramatically decreased the rate of surgery in controlling the acid secretion and likely led to patients presenting with less severe symptoms and fewer complications. (ABSTRACT TRUNCATED)

Morphology and staining patterns of endocrine cell tumours in the gut, pancreas and bronchus and their possible significance

We have studied 109 endocrine cell tumours of the gastrointestinal tract, pancreas and bronchus in terms of histological pattern and histochemical staining with immunocytochemical studies on seven tumours. As a result we believe that previous histological classifications need modification. 5-Hydroxytryptamine secreting tumours have a carcinoid (A1) pattern with, in some cases, an additional tubuloacinar element (A1A2) and definable histochemical reactions; well differentiated gastrinomas, insulinomas and glucagonomas are associated commonly, but not exclusively, with particular histological patterns and argyrophilia, but no such association exists for less differentiated tumours. This may be related to the synthesis of precursor hormones by less differentiated tumours. Mixed patterns are common, particularly in tumours of foregut derivation. Prospective studies planned to correlate histology, histochemistry, immunocytochemistry and ultrastructure are needed on all endocrine cell tumours.

Histologic characteristics of insulinomas and gastrinomas. Value of argyrophilia, metachromasia, immunohistology, and electron microscopy for the identification of gastrointestinal and pancreatic endocrine cells and their tumors

In a first step of our investigation the staining characteristics, especially the argyrophilia and metachromasia, of immunohistologically identified endocrine cells of the pancreatic islets and of the gastroduodenal mucosa were tested. These staining characteristics were then examined on insulinomas and gastrinomas. Contrary to normal B cells which generally react positively with aldehyde fuchsin and pseudoisocyanine but not argyrophilic with the Grimelius method, the neoplastic B cells give inconsistent results with conventional staining methods. Yet neoplastic B cells often show argyrophilic structures. Immunohistologically, most benign insulinomas are rich in insulin-containing cells, whereas in malignant types such cells are rare. The carcinomas, however, show a typical and distinct Grimelius argyrophilia. The tumor cells of gastrinomas are Grimelius argyrophilic and slightly metachromatic, as normal G cells, yet, contrary to A1 cells, they are only exceptionally stainable with the Hellerström method. Despite the great number of Grimelius positive tumor cells, generally only a few reacted with antigastrin serum. Nevertheless, the immunohistology is the most reliable method for the diagnosis of gastrinomas. Electron microscopic results are often difficult to interpret, since gastrinomas, as well as undifferentiated or malignant insulinomas, may predominantly contain atypical secretion granules.

Storage granules of thyroid C cells in the dog: a cytochemical and ultrastructural study, in relation to the masked metachromasia reaction

Masked metachromasia can be demonstrated in thyroid C cells, and other cells of the APUD series, by staining with a metachromatic basic dye after hydrolysis of suitably fixed tissue. The reaction is thought to be due to the presence of polypeptides with a high concentration of side-chain acidic groups. Since most APUD cells possess storage granules, presumed to contain a polypeptide hormone, it has been assumed that the masked metachromasia reaction gives information concerning the contents of these granules. However, there has been an increasing suspicion that the reaction might actually be due to the membrane bounding these granules, rather than to the contents. We have examined, cytochemically and ultrastructurally, dog thyroid tissue which has been subjected to fixation and hydrolysis as in the usual method for masked metachromasia. We found that the membrane surrounding the C cell granules is removed by hydrolysis, confirming the hypothesis that the reaction is due to the contents (hormone and/or matrix)rather than to the membrane. Tissues were fixed in an aqueous mixture containing glutaraldehyde (6 25% v/v), picric acid (three-quarters saturation) and sodium acetate (I% W/V)adjusted to PH 7 with sodium hydroxide. This was found to be a very satisfactory fixative for electron microscopy Some morphological details of C cells were noted, such as the richness of desmosomes between C cells in this species, and frequent direct contact with the colloid.

Formaldehyde-ozone-induced fluorescence in gastrin-producing tumours

Material from eight peptide hormone-secreting tumours, extirpated from the pancreas or from the antrum-duodenum region, was examined. Four of the patients had the clinical manifestations of the Zollinger-Ellison syndrome, two showed the features of an insulin-secreting tumour and one had a glucagonoma. Gastrin-producing cells, identified by immunohistochemistry, were found in five of the tumours. These cells displayed a varying degree of formaldehyde-ozone-induced fluorescence. This agrees with previous observations on the gastrin cell of human antral and duodenal mucosa. From model experiments, formaldehyde-ozone-induced fluorescence is thought to reflect the presence of peptides having tryptophan in the NH2-terminal position. The nature of this peptide in gastrin-producing cells is unknown.

Pathomorphologic, biochemical, and diagnostic aspects of gastrinomas (Zollinger-Ellison syndrome)

The clinical symptomatology of the Zollinger-Ellison syndrome and the pathologic anatomy of gastrinomas are reviewed. Experience with 17 patients with the Zollinger-Ellison syndrome is presented with special reference to stimulation tests (secretin, glucagon, calcium infusion, test meal) and to localization and immunohistologic, ultrastructural, and biochemical findings in gastrinomas. Multiple hormone production by the tumors is frequent. The ultrastructure and the Sephadex G-50 gel filtration patterns of immunoreactive gastrin in sera and tumors are not uniform and are not related to localization of the tumors in the pancreas or duodenum or to the gastrin concentration. Hyperplasia of the pancreatic islets is a frequent finding in gastrinoma patients, suggesting that hypergastrinemia may stimulate islet growth.

Two types of Zollinger-Ellison syndrome: immunofluorescent, cytochemical and ultrastructural studies of the antral and pancreatic gastrin cells in different clinical states

In this survey the antral, pancreatic and, where present, the neoplastic gastrin cells, were studied in eight cases of the Zollinger-Ellison syndrome. The antral G cells alone were studied in one case of Z-E syndrome, seven cases of simple duodenal ulcer, and five cases of pernicious anaemia. The Z-E cases were divided into two numerically equal groups. The first group had ;short' histories, high serum gastrin levels, and profound antral G cell hyperplasia. The second group had ;long' histories, relatively lower serum gastrin levels, normal antral G cells, and either pancreatic D cell hyperplasia or gastrinoma. Antral G cell hyperplasia, with maximal gastrin storage and normal serum gastrin levels, was found in the duodenal ulcer cases. Antral G cell hyperplasia with minimal storage and high serum gastrin levels was observed in the cases of pernicious anaemia. On the basis of our findings we propose that there exist at least two distinct types (or perhaps stages) of the Z-E syndrome. Suggestions for their pathogenesis are offered.

Studies on the G cells of the pyloric mucosa, the probable site of gastrin secretion

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The endocrine cells in the epithelium of the gastrointestinal mucosa of the rat. An electron microscope study

The authors of this study examine the question of whether the so-called enterochromaffin or argentaffin cells of the gastrointestinal tract should be considered as a single cell type. The systematic application of purely morphologic methods has led to the conclusion that the epithelium of the gastrointestinal mucosa comprises endocrine cells of several types. This conclusion is primarily based on the uneven and characteristic distribution of the various cell types along the intestinal tract, an observation precluding the interpretation that the different types correspond to diverse functional stages of the same cell. A specific endocrine function may be attributed to each of the given cell types recognized so far on account of their appearance and their localization in characteristic areas of the gastrointestinal tract. It is acknowledged, however, that a purely morphological study leaves room for doubt. The first cell type is probably responsible for the formation of 5-hydroxytryptamine. Cells of type II are morphologically comparable to the pancreatic A cells and may, therefore, be called intestinal A cells. Cell type III comprises intestinal D cells since their appearance corresponds to that of pancreatic D cells. Cell type IV might well be responsible for catecholamine production, whereas gastrin is in all probability produced in endocrine cell type V. As yet, the thorough morphological study of the gastrointestinal epithelium does not provide information as to additional distinct cellular sites of production of the several other hormones isolated from different parts of the gut.