Glycocalyceal bodies and their role in tumor typing.

Glycocalyceal bodies are membrane-bound vesicles found on the apical surface of intestinal epithelial cells and their neoplastic equivalents. They are believed to arise either from budding of the apical plasma membrane, through discharge from intracytoplasmic vesicles or through both of these mechanisms. Glycocalyceal bodies should be distinguished from particles of inspissated glycocalyceal material as well as from the vesicles that form following microvillous disintegration due to cell injury. There is also a superficial resemblance between glycocalyceal bodies and the membrane vesicles found among the lumen-lining microvilli in both normal and neoplastic sweat ductal epithelium. The chief value of glycocalyceal bodies in diagnostic electron microscopy lies in their role as a marker for intestinal differentiation in tumors. Their exact function is unknown.