Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Based on the light microscopic, electron microscopic and histochemical observations, the pancreatic adenoma is a Apudoma arising from the Islet cell.

The histologic characteristics of functioning and clinically silent lesions are identical. The cells, wich often seem comparable to beta cells of normal islets, tend to occur in ribbons or cords, with only occasional solid masses or glandular structures. Degenerative changes such as fibrosis, hyalinization, or calcification may be present. In our case I don´t identified deposition of the calcification, amyloid and psammoma bodies.The severity of the clinical episodes does not correlate with the size of the islet cell tumor. (3,4,6) Three patterns are observed: (a) a solid, diffuse pattern; (b) a ribbonlike, trabecular pattern; and More than one of these architectural patterns may occur in the same neoplasm. Islet cell tumors are composed of sheets of small round cells. Mitoses are unusual. The amount of intervening stroma is extremely variable, and the stroma may appear dense and hyalinized. This tumors are liable to degenerative change and fibrosis. There is a well-organized relationship between the neoplastic cells and the numerous stromal vessels. These vessels are responsible for the hypervascular nature of the lesions. (5)

Immunohistochemical staining does not allow differentiation among the different types of functioning islet cell tumors nor does it allow reliable separation between functioning and clinically silent tumors. (3,5)

The Insulinoma is classified into four kinds according to the ultrastructural characteristics of the granules (3,7):

Type I : Tumor with cells containing typical B-cell granules.
Type II: Tumors with cells containing typical and atypical secretory granules.
Type III: Tumor with cells containing only atypical secretory granules.
Type IV: Tumor composed almost enterily of agranular cells.
In our case it can be of type II.

Conclusion

We report one case of insulinoma of pancreas with clinicopathological and ultrastructural analysis.  

Back to the top.