Observing the normal mucosa lymphatic vessel morphology and construction of human colorectum.To supply morphological theory for researching the colorectal carcinoma lymphatic metastasis path.

After immunohistochemisty of the serial section of human colorectal paraffin-embedded specimen, observe the expression of lymphnodes by the light microscope, and observe the mucosa ultrathin section through the electron microscope to detect lymphatic vessel ultrastructure.

After the D2-40 monoclonal antibody immunohistochemisty staining, light brown colorations are distributing in the lamina muscularis mucosae and in the level between the amina propria and lamina muscularis, a few of them have thin or unintegrity vessel wall and small lumens, which have no overlap with CD34 staining.A few of lymphatic vessel walls in mucosa are very thin, which are composed of a layer of endotheliocyte.There is no aperture or pericyte and the basement membrane is discontinuous or congenitally absent.Endotheliocyte form end-to-end conjunction, overlap conjunction or insertion conjunction .There is anchoring filaments connecting in outside of the vessel wall.

Lymphatic vessel exists in normal colorectal mucosa which is located between the lamina and muscularis mucosae and in the muscularis mucosae, and there is likely to be path to the lymphatic vessel of stratum submucosum, so it makes lymphatic metastasis possible in anatomy.