Cancer of gastrointestinal tract is one of the common types of malignancies occurring in human race. The diagnosis of GIT tumors can be made easily with haematoxylin and eosin stained sections but immunohistochemistry is needed in few cases as diagnostic and prognostic marker. AIM: The aim of the study was to study the incidence of expression of cytokeratin 20 in various gastrointestinal malignancies of different histological types along with their metastases if any. With the above aim in mind 40 cases of gastrointestinal malignancies, primary and metastases in lymph node, submitted in the Department of Pathology, Government Medical College, Amritsar were included in the study.

MATERIAL AND METHOD: The formalin fixed and paraffin embedded sections were cut and stained with routine haematoxylin and eosin (H & E) for histological typing of tumor. These cases were further subjected to immunohistochemical staining for cytokeratin 20 using primary antibody: Ready to use mouse monclonal anti human cytokeratin 20 protein, clone Ks 20.8 (Novocastra).The immunostaining results were assessed semiquantitatively. RESULTS: The Cytokeratin 20 seems to be a suitable adjunct marker to evaluate the primary origin of carcinomas in specific context, especially to separate metastatic adenocarcinomas of gastrointestinal versus non–gastrointestinal origin.