vasoactive-intestinal-peptide and Apudoma

Histopathological and experimental observations indicate that tumors composed wholly or in part of neuroendocrine elements may arise in tissues derived from ectoderm (including neuroectoderm), mesoderm, and endoderm. These tumors frequently exhibit multidirectional differentiation as manifested by multihormonality and by the presence of morphological features indicative of divergent differentiation both in vivo and in vitro. The existence of stem cells, plasticity of differentiated cells, microenvironmental influences, and random events are factors which might all interact to determine the characteristics of any particular tumor. The production of characteristic regulatory peptide products in association with tumors of specific histological subtypes and with other neuroendocrine markers suggests mechanisms for nonrandom activation of multiple genes common to neuroendocrine-programmed cells. Future studies applying new molecular biological techniques to intact tissues and to in vitro models may help to clarify the mechanisms that regulate the expression of the neuroendocrine phenotype in normal and neoplastic states.

Topics: Adrenal Gland Neoplasms; Animals; Apudoma; Calcitonin; Carcinoid Tumor; Cricetinae; Female; Gastrins; Hormones, Ectopic; Humans; Neurotensin; Ovarian Neoplasms; Pancreatic Neoplasms; Pheochromocytoma; Rats; Somatostatin; Thyroid Neoplasms; Uterine Neoplasms; Vasoactive Intestinal Peptide

As sensitive radioimmunoassays for the detection of polypeptide hormones are developed, the exciting discovery of a diffusely distributed system of interrelated endocrine cells has begun a new era of endocrinology. This system, although anatomically disassociated, is bound together by a number of common features such as its biosynthetic mechanism, histochemical and ultrastructural features, and embryologic origin (Table I). The most prominent feature, however, is their biosynthetic pathways for hormone production, from which the acronym APUD has been derived. These are the capacity for Amine Precursor Uptake such as DOPA and then subsequent Decarboxylation, resulting in the synthesis of bioactive amines or polypeptide hormones. Hyperplasias or neoplasms of these cells are defined as apudomas. In the last ten years a great deal of research has rapidly altered the original concepts of this system, especially in terms of its embryologic origin, physiologic interrelationships, classification, as well as the addition of many new APUD cell members. These will be reviewed, and the origin, diagnosis, and treatment of each recognized apudoma will be synthesized in light of its membership within the APUD system.

Topics: Adenoma, Islet Cell; APUD Cells; Apudoma; Carcinoid Tumor; Carcinoma; Endocrine Glands; Humans; Neural Crest; Neuroblastoma; Paraganglioma; Pheochromocytoma; Pituitary Neoplasms; Somatostatin; Thyroid Neoplasms; Vasoactive Intestinal Peptide

The identification and description of a widely dispersed group of cells of common origin and biochemical characteristics, APUD cells, has allowed a better understanding and classification of endocrine tumors of the pancreas. Similarly, it has enabled the relationships between the endocrine tumors of the multiple endocrine neoplasia type I syndrome and the endocrine tumors of the pancreas to be better appreciated. This has facilitated both diagnosis and management of these conditions. The pluripotentiality of the cells of the APUD system combined with the certain existence of many unidentified peptides suggests the likelihood of other undescribed pancreatic endocrine tumors. Many of these are probably part of the heterogenous group of neoplasms currently designated as carcinoids, since their secretory products and exact cell types are not known. The recognition of the physiologic characteristics and cells of origin of these peptides, amines or other bioactive agents will allow delineation of the symptom complex and the identification of further functional tumors of the pancreas. The development of plasma radioimmunoassays for the various hormones and the appreciation of the specific clinical syndromes related to each tumor have enabled earlier diagnosis. The understanding of the hormonal physiopathologic functions has led to the evolution of specific therapeutic maneuvers. Provocative tests have allowed increased precision of the differential diagnosis, while selective arteriography and pancreatic venous sampling have greatly enhanced the accuracy of topical localization. The role of operation in tumor removal is still prominent, but malignant and recurrent tumors may now also be controlled with specific pharmacotherapy or appropriate endocrine cytotoxic agents. The use of peptides with antagonistic actions or the administration of specific antibodies to the active tumor products are areas of therapy that require further exploration.

Topics: Adult; Apudoma; Carcinoid Tumor; Child; Diagnosis, Differential; Gastrins; Glucagon; Humans; Infant; Insulin; Insulin Secretion; Islets of Langerhans; Neoplasms, Multiple Primary; Pancreatic Neoplasms; Pancreatic Polypeptide; Somatostatin; Vasoactive Intestinal Peptide; Zollinger-Ellison Syndrome

A series of 25 apudomas of the gastrointestinal tract (22 cases), bronchus (2 cases), and thymus (1 case) were subjected to staining with silver impregnation (Masson-Fontana and Grimelius) techniques and with the commercial immunoperoxidase kits for the peptide hormones adrenocorticotropin, calcitonin, gastrin, glucagon, growth hormone, human chorionic gonadotropin (hCG), insulin, somatostatin, and vasoactive intestinal peptide. Of the tumors studied, 16 were regarded as malignant, and 5 of the patients showed clinical symptoms due to inappropriate hormone secretion. A total of 16 tumors contained cells positive for 1 or more (6 were multihormonal) of the hormones studied. One bronchial carcinoid stained for hCG, which has not been previously reported. In addition, one of the rectal carcinoids contained somatostatin-positive cells, only once described previously. The thymic tumor proved frankly malignant, most probably identical to the oat-cell carcinoma recently described. The findings also substantiate the recent suggestion that gastrointestinal carcinoids cannot be adequately classified on the basis of silver stains only and strongly advocate the use of the immunoperoxidase kits in routine assessments of all the endocrinologically active tumors, whatever their localization might be.

Topics: Adrenocorticotropic Hormone; Adult; Aged; Apudoma; Bronchial Neoplasms; Calcitonin; Chorionic Gonadotropin; Female; Gastrins; Gastrointestinal Neoplasms; Glucagon; Growth Hormone; Humans; Immunoenzyme Techniques; Male; Middle Aged; Peptides; Somatostatin; Thymus Neoplasms; Vasoactive Intestinal Peptide

An unusual tumor of the skin was removed from the thigh of a 52-year-old white male. By light microscopy, the tumor was composed of intermediate and small cells in sheets and clusters. Ultrastructural study of the tumor cells showed numerous dense core granules and dendritic cell processes as well as intermediate filaments and cell junctions frequently within the same cells. Most of the tumor cells were stained intensely by antibodies to neurone-specific enolase (NSE), a marker of cells of the central and peripheral nervous system. The neuropeptides met-enkephalin and vasoactive intestinal peptide (VIP) were also found in tumor cells. Immunohistochemistry furthermore demonstrated cytokeratin. Both the ultrastructural appearance and keratin content of this tumor set it apart from conventional Merkel cell (or trabecular) carcinoma of the skin in a manner analogous to bipartite (i.e., epidermoid and small cell) carcinoma of lung. The production of neuropeptides simultaneously with the production of keratin establishes this as a bipartite skin tumor (i.e., ectodermal and neuroectodermal phenotype). We suggest that at least some primary neuroendocrine tumors of the skin arise from multipotential ectodermal cells not of neural crest origin, as has been proposed for small cell carcinoma of lung.

Topics: Apudoma; Cytoplasmic Granules; Enkephalin, Methionine; Humans; Keratins; Male; Microscopy, Electron; Middle Aged; Phosphopyruvate Hydratase; Skin; Skin Neoplasms; Vasoactive Intestinal Peptide

Two patients have been studied with a two and a half and nine year history of metastatic pancreatic apudoma. In both patients the main feature was chronic watery diarrhoea with remissions after partial tumour resection and streptozotocin therapy. Plasma levels of circulating VIP and neurotensin were persistently raised in both patients. Chromatographic analysis of the plasma showed that a significant proportion of the raised immunoreactivity of both peptides eluted in an identical position to pure VIP and neurotensin. The extremely high concentrations of neurotensin did not appear to result in any feature which would allow distinction from the classical VIPoma syndrome.

Topics: Adult; Apudoma; Female; Gastrointestinal Hormones; Humans; Male; Middle Aged; Neurotensin; Pancreatic Neoplasms; Vasoactive Intestinal Peptide

A case of non-beta islet cell tumor of the pancreas with elevated vasoactive intestinal polypeptide (VIP) levels and WDHA syndrome (watery diarrhea, hypokalemia, and achlorhydria) was studied. Angiography and radio isotope scanning showed profuse abnormal vascularity. Ultrasonography showed a solid mass with small- to medium-sized cystic spaces. Histologic examination with special staining (Sevier-Munger) showed carcinoid tumor.

Topics: Angiography; Apudoma; Female; Humans; Islets of Langerhans; Middle Aged; Pancreatic Hormones; Pancreatic Neoplasms; Ultrasonography; Vasoactive Intestinal Peptide

A female patient is described with a single pancreatic tumour producing vasoactive intestinal polypeptide (VIP), insulin, and pancreatic polypeptide. The initial presentation was with diarrhoea and hypokalaemia and a raised plasma VIP was demonstrated. Her symptoms improved with metoclopramide administration and absolute concentrations of 28 aminoacid (peak IV) VIP were found to have fallen. She then developed hypoglycaemia with hyperinsulinism. All symptoms resolved after surgical excision. This case emphasises the potential of these tumours to contain more than one endocrine cell type synthesising different biologically active peptides.

Topics: Apudoma; Diarrhea; Female; Gastrointestinal Hormones; Humans; Insulin; Insulin Secretion; Metoclopramide; Middle Aged; Pancreatic Neoplasms; Pancreatic Polypeptide; Vasoactive Intestinal Peptide

Insulinoma, glucagonoma, gastrinoma (Zollinger-Ellison syndrome), vipoma, somatostatinoma and a tumor that secretes human pancreatic polypeptide are the primary endocrine-secreting tumors of the pancreas. hormones are produced by specific tumor cell types and cause a variety of dramatic clinical pictures. Diagnosis often requires hormone assays. Computerized tomography may be helpful. Definitive surgical treatment is possible, but metastases may be present.

Topics: Adenoma, Islet Cell; Apudoma; Gastrins; Glucagon; Humans; Insulin; Insulin Secretion; Pancreatic Neoplasms; Pancreatic Polypeptide; Somatostatin; Vasoactive Intestinal Peptide; Zollinger-Ellison Syndrome

An APUD adenoma of the right adrenal was discovered in an adult after angiography and compted tomography The tumor had provoked a WDHH syndrome. Selective venous sampling before operation demostrated the presence in the tumor of hormonal secretions (VIP and catecholamines). The patient recovered after excision of the tumor, which contained large quantities of intracellular somatostatin and VIP.

Topics: Achlorhydria; Adrenal Gland Neoplasms; Angiography; Apudoma; Catecholamines; Diarrhea; Gastrointestinal Hormones; Hypokalemia; Somatostatin; Syndrome; Vasoactive Intestinal Peptide

Topics: Achlorhydria; APUD Cells; Apudoma; Carcinoid Tumor; Carcinoma; Cholecystokinin; Diarrhea; Endocrine System Diseases; Humans; Hypokalemia; Malignant Carcinoid Syndrome; Neoplasms; Pancreatic Diseases; Paraganglioma; Paraneoplastic Endocrine Syndromes; Peptides; Prostaglandins E; Somatostatin; Syndrome; Thyroid Neoplasms; Vasoactive Intestinal Peptide

With the advent of radioimmunoassay and immunocytochemical methods, the peptides of the gastrointestinal tract have been identified and measured. Gastrinoma and insulinoma syndromes have been wall characterized. The pancreatic cholera syndrome and some of the evidence that the major manifestations of this disease may be mediated by vasoactive intestinal peptide have been re-examined. Pancreatic polypeptide seems to be an ideal peptide for study of vagal-cholinergic mechanisms that regulate hormone release; it also appears to be a tumor marker for several types of pancreatic endocrine tumors, particularly those of pancreatic cholera. Secretin and cholecystokinin are important regulators of pancreatic exocrine secretion and have been used to test pancreatic function, but there is little evidence that they account for clinical disease. Glucagon-secreting tumors produce a clinical syndrome of diabetes mellitus and distinctive skin lesions, which can be cured by tumor resection. Hormone-secreting tumors may provide insight into normal gut physiology.

Topics: Adenoma, Islet Cell; Animals; Apudoma; Cholecystokinin; Diarrhea; Dogs; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Hormones; Humans; Intestines; Pancreas; Pancreatic Neoplasms; Pancreatic Polypeptide; Stomach; Stomach Neoplasms; Vasoactive Intestinal Peptide

Pancreatic apudomas are not common but are frequently curable. Thus, it is important for every clinician to be fully aware of the varied clinical syndromes that suggest their presence. The availability of specific radioimmunoassays has made confirmation of the diagnosis relatively simple. Advances in the techniques for staining the different cell types have led to the recognition that many of these tumors are mixed, and that the general term "pancreatic apudoma" is appropriate. Pancreatic endocrine tumors, as examples to "nature's experiments," have yielded considerable insight into the possible physiologic effects of the various peptides they produce. It is to be hoped that further study of tumors such as the somatostatinoma and PPoma may yield further information about these enigmatic compounds.

Topics: Animals; Anura; Apudoma; Dogs; Gastrins; Gastrointestinal Hormones; Glucagon; Humans; Insulin; Insulin Secretion; Pancreatic Neoplasms; Pancreatic Polypeptide; Somatostatin; Vasoactive Intestinal Peptide

Topics: Apudoma; Carcinoid Tumor; Female; Gastrins; Gastrointestinal Neoplasms; Glucagon; Humans; Insulin; Insulin Secretion; Pancreatic Neoplasms; Pancreatic Polypeptide; Somatostatin; Vasoactive Intestinal Peptide

A patient is described who presented with the classical symptomatology and profound electrolyte disturbance of the Verner-Morrison syndrome due to a pancreatic apudoma secreting vasoactive intestinal polypeptide (VIP). Diagnosis was confirmed by plasma VIP as measured by a radio-immunoassay technique now available. It is suggested that the cyclical nature of the symptoms in this case was due to cyclical release of VIP from the tumour in response to an unknown stimulus. Perfusion studies confirmed the excess secretory state of water, sodium and chloride in the small intestine. Symptoms were completely abolished by surgery and the progress is being monitored by means of serial plasma VIP estimations to detect any early recurrence of metastatic disease.

Topics: Adenoma, Islet Cell; Aged; Apudoma; Female; Gastrointestinal Hormones; Humans; Pancreatic Neoplasms; Syndrome; Time Factors; Vasoactive Intestinal Peptide