A pancreatic tumour with carcinoid syndrome and ypoglycaemia

Serotonin-producing enterochromaffin cell tumors of the pancreas: clinicopathologic study of 15 cases and comparison with intestinal enterochromaffin cell tumors

OBJECTIVES

Serotonin-producing tumors of the pancreas are rare endocrine neoplasms composed of enterochromaffin (EC) cells that have been mainly described in the literature as case reports. This study analyzes the clinicopathologic features of a series of pancreatic EC cell neoplasms and their similarities to and differences from intestinal EC cell tumors.

METHODS

The morphological, immunohistochemical, ultrastructural, and fluorescent in situ hybridization features of 15 pancreatic and 20 intestinal serotonin-producing neoplasms were compared. In addition, we reviewed the literature on pancreatic serotonin-producing tumors to better understand the clinicopathologic features of this rare tumor type.

RESULTS

The lack of substance P and acidic fibroblast growth factor immunoreactivity; the low immunohistochemical expression of CDX2, vesicular monoamine transporter 1, connective tissue growth factor, and prostatic acid phosphatase; the lack of S100-positive sustentacular cells; the strong expression of vesicular monoamine transporter 2; and peculiar ultrastructural features characterize pancreatic EC cell tumors and differentiate them from intestinal ones, although both categories show similar chromosome 18 cytogenetic alterations. The review of the literature indicates that pancreatic functioning tumors associated with the carcinoid syndrome arise in younger patients and are larger, more frequently malignant, and more aggressive neoplasms than pancreatic nonfunctioning ones.

CONCLUSIONS

Pancreatic EC cell tumors show several different morphological features compared with related intestinal tumors despite similar cytogenetic alterations on chromosome 18.

Sequential hypoglycemia, hyperglycemia, and the carcinoid syndrome arising from a plurihormonal neuroendocrine neoplasm

OBJECTIVE

To describe the first patient with a neuroendocrine tumor secreting serotonin, insulin, and glucagon and having the corresponding clinical syndromes.

METHODS

We present a detailed case report, including serial laboratory and clinical findings, in a man with type 2 diabetes, symptomatic hypoglycemia, and the carcinoid syndrome and in whom a plurihormonal metastatic neuroendocrine neoplasm was ultimately diagnosed.

RESULTS

In a 58-year-old man with type 2 diabetes, which was treated effectively with a sulfonylurea for 7 years, episodes of hypoglycemia developed. After discontinuation of the orally administered agent, the hypoglycemic episodes initially resolved but then recurred and were associated with inappropriately increased plasma insulin concentrations. In addition, the patient had symptoms and biochemical evidence of the carcinoid syndrome. Computed tomography of the abdomen showed multiple hypodense lesions in the liver, and ultrasound-guided fine-needle aspiration of a liver mass was performed. Undifferentiated neuroendocrine tumor with hepatic metastatic involvement was diagnosed. After a hepatic artery embolization procedure, the hypoglycemia was alleviated, but hyperglycemia soon recurred, associated with inappropriately increased serum glucagon concentrations. The patient's course strongly suggested the presence of a plurihormonal tumor secreting serotonin, insulin, and glucagon.

CONCLUSION

To our knowledge, this is the first reported case of a patient with a neuroendocrine neoplasm secreting serotonin, glucagon, and insulin, manifested by the carcinoid syndrome, hyperglycemia, and hypoglycemia.

Carcinoid tumors of the pancreas. Status report based on two cases and review of the world's literature

CONCLUSION

The diagnosis of a pancreatic carcinoid should be based on the measurement of serotonin in serum or its demonstration in the tumor and/or by the measurement of its derivative (5-HIAA) in urine. Carcinoid of the pancreas is a rare but definite entity; usually having metastasized by the time of diagnosis. The term "serotonin-producing tumor of the pancreas" has been suggested as an alternative designation for "pancreatic carcinoid."

BACKGROUND

The literature on carcinoid tumors of the pancreas is confusing because much of it preceded the development of the more specific immunological, chemical and staining techniques currently available.

METHODS

43 case reports were collected from the world's literature, based on a demonstrable pancreatic neuroendocrine tumor plus a positive finding of at least one of the following without another dominant hormone being demonstrated: elevation of 5-Hydroxytryptamine (5-HT) (serotonin) in the serum or detected in tumor tissue, and/or elevation of 5-Hydroxyindole acetic acid (5-HIAA) in the urine. In addition to these two hormone-specific assays, information was collected on the silver-staining properties of the tumor; properties which have traditionally been associated with carcinoid tumors. Positive silver staining in tumor cells (argyrophilic and/or argentaffin reaction) is strongly indicative of the carcinoid tumor but the findings are less specific than the hormone assays and immunohistologic stains.

RESULTS

In this review of 43 cases, including two current ones, the pancreatic carcinoid tumor has the following important features: 1. It is a rare tumor that is usually diagnosed late when the tumor is large and has metastasized. Thirty-eight (88.4%) have been malignant. They are, therefore, associated with a high incidence of the "carcinoid syndrome." 2. To date, prognosis in therapy is poor, based on delayed diagnosis, a resultant low incidence of resectability, and an uncertain duration of survival after resection. 3. Pancreatic carcinoid tumors remain difficult to differentiate from other endocrine tumors. The measurement of urinary 5-HIAA excretion or the demonstration of elevated serotonin level in the tumor or in serum is essential to its distinction. Silver staining of the tumor, although of historic importance, has been superceded by the hormone-specific studies. 4. To distinguish it from other endocrine tumors of the pancreas, the terms "pancreatic serotoninoma" or "serotonin-producing tumor of the pancreas" have been suggested as possible alternatives. Its growth characteristics may be related more to its cell of origin than to its extent of hormone secretion. Not all of the tumors result in recognizable hyperserotoninemia.

Pancreatic endocrine tumors

In this review the current state of our understanding of endocrine tumors of the pancreas is considered. It is based on the experience with a series of 365 tumors. The first part of the article focuses on origin and classification, markers, frequency, criteria of malignancy as well as general structural features of the pancreatic endocrine tumors. In the second half of the article the functioning tumors, i.e. tumors that cause hormonal syndromes, and the nonfunctioning tumors as well as the endocrine tumors associated with multiple endocrine neoplasia type 1 are dealt with in detail. Special emphasis is put on the immunocytochemical profile and the biological features of the respective tumors.

Serotonin-secreting and insulin-secreting ileal carcinoid tumor and the use of in vitro culture of tumoral cells

The authors report the case of a patient with a typical carcinoid syndrome and a severe hypoglycemia due to hyperinsulinism. He was found to have an ileal carcinoid tumor with hepatic metastasis and no evidence of pancreatic insulinoma at surgery and autopsy. By assaying serotonin and insulin in the tumor and in the supernatants of the culture derived from hepatic metastasis, the authors have been able to show that both hormones were produced by the carcinoid tissue. Cultured cells also synthesized minute amounts of gastrin and thyrocalcitonin.

Hypoglycemia associated with carcinoid tumors. A case report and review of the literature

The authors report a 73-year-old man with a jejunal carcinoid tumor and spontaneous hypoglycemia. Plasma insulin was suppressed (insulin/glucose ratio, 0.2), and nonsuppressible insulin-like proteins (NSILP) were elevated. Seven other patients with carcinoid or related tumors associated with hypoglycemia were found in the literature. Nonsuppressible insulin-like proteins were not measured in these patients.

Adenocarcinoma of the pancreas associated with hypoglycemia: case report and review of the literature

The occurrence of profound hypoglycemia in a patient with metastatic adenocarcinoma of the pancreas is reported. In contrast to the four previously reported cases, no suggestion of excess insulin production was found. Metabolic studies in this patient suggest both increased peripheral glucose utilization and decreased hepatic glucose production as contributing factors which promoted the hypoglycemia.

Electron microscopy of neoplasms of pancreatic islet cells

Neoplasms of pancreatic islet cells that produce widely divergent clinical syndromes cannot be distinguished from one another by conventional microscopy. Differentiation among these tumors by electron microscopy is possible in some cases only. Coordinated clinical evaluation, histochemical and ultrastructural studies, and assay of serum and neoplastic tissue for various polypeptide hormones afford the best characterization of these neoplasms.

Ectopic insulin and Occam's razor: reappraisal of the riddle of tumour hypoglycaemia

The concept of ectopic insulin production is challenged on the basis of a review of 120 cases from the literature on extrapancreatic tumours associated with hypoglycaemia in which insulin or insulin-like activity were measured. No case met two or more of five criteria of ectopic hormone production. The evidence indicates that hypoglycaemia of extrapancreatic tumours cannot be attributed to insulin. In those rare cases in which plasma insulin was reported as high, pancreatic beta-cells could not be excluded as the source of insulin. Interestingly, many of these dubious cases had carcinoid histology. The review also points out a close association between some spindle-cell tumours and carcinoid tumours which may be relevant to discussion on the disputed origin of some "mesothelial" tumours. Nonsuppressible insulin-like activity (NSILA) consists of a number of factors mimicking insulin activity which compete with insulin or proinsulin for membrane receptors and may crossreact in bioassays, immunoassays, and receptor assays. The question of whether one or several of these substances may be responsible for extrapancreatic hypoglycaemia remains to be elucidated.

The carcinoid endocardial plaque; an ultrastructural study

Ultrastructural studies disclosed that the plaque-like endocardial thickenings in three patients with the carcinoid syndrome were composed of smooth muscle cells embedded in a stroma that was rich in acid mucopolysaccharides, collagen, and microfibrils, but devoid of elastic fibers. The smooth muscle cells contained variable numbers of myofilaments and cisterns of rough surfaced endoplasmic reticulum, and their basement membranes were greatly thickened, reduplicated, and arranged in layers. The endocardial plaques appeared histologically and ultrastructurally similar regardless of their location in the heart. The smooth muscle cells in these plaques appear to have been derived from primitive mesenchymal cells, which normally are present in the subendocardial endothelial space. These observations are interpreted as indicating that the plaques develop as a result of healing of a superficial endocardial injury, which may be initiated by release of bradykinin from hepatic metastases of a carcinoid tumor.