PROTEIN EXPRESSION OF CHROMOGRANIN A, SYNAPTHOPHYSIN AND KI-67 IN DETECTING NEUROENDOCRINE NEOPLASM IN HIGH GRADE COLORECTAL ADENOCARCINOMA CASES
Gusti Deasy W. Ariani1, Upik A. Miskad1, M. Husni Cangara1, Andi Alfian Zainuddin2, Syarifuddun Wahid1, Djumadi Ahmad1.
1 Department of Anatomic Pathology, 2Department of Public Health, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
ABSTRACT
Background. Neuroendocrine neoplasm (NEN) is a type of tumor originating from neuroendocrine epithelial cells that has a microscopic appearance similar to high-grade colorectal adenocarcinoma. To establish the diagnosis of NEN, immunohistochemically expressed protein markers such as chromogranin A, synaphtophysin and Ki-67 are needed. This study aims to determine whether there are cases of neuroendocrine neoplasms in samples that previously diagnosed as high grade colorectal adenocarcinoma based on the expression of the these protein markers.
Materials and methods. Seventy paraffin blocks samples previously diagnosed as high grade colorectal adenocarcinoma were stained immunohistochemically to detect the expression of chromogranin A, synapthophysin and Ki-67 proteins. Description analysis was performed to determine the number of cases of NEN in these stained samples.
Results. We found that totally 8 (11.4%) samples of NEN from seventy samples previously diagnosed as high-grade colorectal adenocarcinoma. Of these 8 NEN samples, there were 3 (1.4%) samples that diagnosed as neuroendocrine tumors (NET) and 5 (7.1%) samples were diagnosed as Large cell neuroendocrine carcinoma (LCNEC).
Conclusion. Neuroendocrine neoplasms have a microscopic appearance that similar to high-grade colorectal adenocarcinoma. There were several cases of NEN that found in samples previously diagnosed as high-grade colorectal adenocarcinoma in this study. Therefore, it is necessary to detect the expression of protein markers such as chromogranin A, synaptophysin and Ki-67 to diagnose neuroendocrine neoplasms (NEN).