Pancreatic Pathology Online: Enterochromaffin cell (Carcinoid) Tumours

Enterochromaffin cell (EC cell) carcinoid tumours of pancreatic islets that elaborate serotonin are rare.

The benign variant induces the so-called atypical carcinoid syndrome, consisting of a severe facial flush, hypotension, periorbital edema, and lacrimation.

The malignant variant metastasizes to the liver and causes the classic carcinoid syndrome, which is additionally associated with endocardial fibrosis of the right heart.

Histologically, the primary pancreatic enterochromaffin cell (EC cell) carcinoid tumour is usually composed of uniform round cells, proliferating in small nests or trabeculae. The tumor cells are strongly positive with both Grimelius and Fontana-Masson stains.

The immunohistochemical study reveal that the tumour cells are positive for serotonin and chromogranin.

Some islet cell tumours with the histologic features of carcinoid tumours have contained products other than serotonin, such as insulin, gastrin, vasoactive intestinal peptide calcitonin, and prostaglandins.

Primary carcinoid tumor of the pancreas.

Carcinoid tumor of the pancreas with obstructive pancreatitis.Am J Gastroenterol. 1992 Mar;87(3):361-4.

A case of primary pancreatic enterochromaffin cell (EC cell) carcinoid tumor in a 66-yr-old Japanese man is presented. The markedly dilated main pancreatic duct was noticed at the time of an incidental ultrasonogram during hospitalization for diabetes mellitus. Endoscopic retrograde pancreatography showed stenosis of the main pancreatic duct at the body of the pancreas and dilated pancreatic ducts distal to the obstruction. A distal pancreatectomy was performed, together with splenectomy. Macroscopically, the main pancreatic duct was compressed by a fibrous mass around the duct, and the pancreatic ducts distal to the tumor were markedly dilated. Histologically, the tumor was composed of uniform round cells, proliferating in small nests or trabeculae. The tumor cells were strongly positive with both Grimelius and Fontana-Masson stains. The immunohistochemical study disclosed the tumor cells to be positive for serotonin and chromogranin. This is a rare case of primary pancreatic EC cell carcinoid tumor with obstructive pancreatitis.

Diagnostic pathology of gastrointestinal and pancreatic neuroendocrine tumours. Acta Oncol. 1989;28(3):363-9.

The increased knowledge of the pathobiology of gastrointestinal and pancreatic neuroendocrine tumours and the improved therapeutic possibilities have brought a demand for more precise diagnosis. Although the neuroendocrine tumours can often be tentatively recognized in routinely processed microscopic slides, their more accurate identification requires additional diagnostic procedures. General neuroendocrine markers, such as the argyrophil reaction of Grimelius and immunohistochemistry with application of antibodies against chromogranin A and of neuron-specific enolase are discriminatory staining methods which are used to reveal the neuroendocrine origin of almost all highly differentiated neuroendocrine tumours of the gastrointestinal tract (carcinoids) and pancreas (insulomas). Midgut carcinoids, which predominate among these tumours almost unexceptionally contain serotonin. This biogenic amine can be demonstrated by the argentaffin reaction of Masson, serotonin immunoreactivity or by formalin-induced fluorescence. The characteristic staining pattern of midgut carcinoids is almost invariably preserved in the metastases and can thus be used to reveal a primary midgut carcinoid. The enterochromaffin-like (ECL) cell carcinoids of the body and fundic area of the stomach are argyrophil with Sevier-Munger silver stain. Other neuroendocrine tumours, viz, antral, duodenal and rectal carcinoids and insulomas, should be studied by a battery of relevant peptide hormone antisera for adequate diagnosis. About 50% of all insulin-producing insulomas are endowed with stromal amyloid deposits, which chemically are composed of a peptide designated islet amyloid polypeptide. This molecule has been observed by electron microscopical immunocytochemistry to occur exclusively in the beta-cells and is co-stored with insulin in the beta-cell granules.

August 2007