Background : Because of bad prognosis, nonspecific signs and high incidence, carcinoma of the colon is one of the leading cause of cancer-related mortality. Recent studies have proposed the role of cell surface glycoconjugate in the course of neoplasia changes. These compounds are used to clarify early diagnosis, prognosis, biologic behaviour of neoplastic cells, and of course, an appropriate therapeutic approach. The aim of the present study was to identify the Gal/GalNac in cell surface glycoconjugate of polyp and adencocarcinoma of colon.

Materials and methods : It was a descriptive study. Pathologic blocks of 47 patients with polyp and adenocarcinom of colon admitted to Khatam-Al-Anbia hospital in Zahedan were reviewed. Having confirmed the diagnosis, 5-7 m m sections were prepared form suitable paraffin blocks of 10 patients (5 polyp & 5 adenocarcinoma) and lectin histochemistry using PNA staining was achieved (lectin dilute 10 m g/ml in PBS 0.1 M, pH = 6.8 and alcian blue pH=2.5).

Results : Results showed existence of Gal/GalNac in entrocytes of polyp cells in region of nuclei and supranuclear portion of the cytoplasm. However, cancerous cells showed the presence of this terminal sugar principally in luminal surface and intraluminal secretion of glandular components. The cell-reaction to lectin was higher in neoplastic cells than entrocytes of polyp. Therefore the existence of Gal/GalNac was confirmed in cytoplasm of entrocytes of polyp and luminal surface of neoplastic cells in adenocarcinoma of colon.

Conclusion : Results have revealed that the degree and location of reactivity of cells to lectins were changed in neoplasia.