Dispersed neuroendocrine system (D.N.S) consists of a wide variety of cells that are present in the central and peripheral nervous system and in many classic endocrine organs and different tissues such as respiratory and gastrointestinal tracts, skin, prostate, breast and also their neoplasm show neuroendocrine differentiation by electron microscopy, immunohistochemistry or biochemical techniques:
Materials and Methods: The present study has been carried out by case-series method in order to evaluating the characteristics of all types of neuroendocrine carcinoma: different anatomical locations during 5 years period in immunohistochemistry department of cancer institute.
Results: The diagnosis of 109 cases of neuroendocrine carcinoma consisting of neuroendocrine carcinoma, small cell carcinoma, medullary carcinoma of thyroid, carcinoid tumor and merkel cell carcinoma are confirmed that among them the most common diagnosis was related to neuroendocrine carcinoma (50.5 percent). The most prevalent age group was 40-49 years and male to female distribution were 56 percent and 44 percent respectively. Anatomical distribution of tumor show that about 30 percent of cases were metastatic carcinoma, 30 percent in thyroid, respiratory tract and head and neck region and remainder in a variety of tissues. In over 50 percent of cases one of endocrinoid patterns as trabecular, organoid or mixed of them were seen.
Conclusion: Immunohistochemically N.S.E (Neuron Specific Enolase) show high sensitivity with 96 percent positive reaction and more specific endocrine markers as chromogranin A in 80 percent and synaptophysin only in 24 percent because of lesser application of the latter. Also epithelial markers such as cytokeratin and E.M.A.
(Epithelial Membrane Antigen) were positive in 69 percent and 74 percent respectively. Mean survival rate of all neuroendocrine carcinoma reached to 4.8 years with lowest survival of 4.3 years among small cell carcinoma and highest in merkel cell carcinoma with 5.5 years.
