THE ROLE OF IMMUNOHISTOCHEMISTRY IN THE EVALUATION OF UNDIFFERENTIATED GASTRIC CANCER

الملخص

Background: With the advance in medical practices, gastric cancer remains one of the deadly diseases with poor prognosis. Appropriate diagnosis of the histological gastric cancer type may improve the treatment and the prognosis. The objective of this study is to apply immunohistochemical (IHC) markers for the diagnosis of undifferentiated gastric malignancies. Among 126 patients diagnosed as cases with malignant gastric tumors, from September 2008 to September 2013, 55 cases were assigned as undifferentiated tumors and were subjected to IHC evaluation by application of many IHC markers and special stains for further categorization; Results: After the application of different IHC markers and special stains, the 55 cases which were assigned as undifferentiated revealed to be carcinoma (37 cases), lymphoma (9 cases), gastrointestinal stromal tumors (GIST) (7 cases) and leiomyosarcoma and neuroendocrine tumor one case for each. IHC findings had changed the primary diagnoses based on morphological data in 4 instances; two cases were thought to be signet ring carcinoma and proved by IHC to be lymphomas and other two cases were thought to be poorly differentiated adenocarcinoma and proved to be GIST. Therefore; IHC is a valuable tool for the diagnosis of undifferentiated malignant gastric tumors.