[Pathologic changes of lymphatic capillaries after injection of U14 cells in rat tongue perineoplastic area].
OBJECTIVE
1. To establish a model of neck lymphatic metastasis of cancer by injecting tumor cells into the rat tongue; 2. To observe the relationship between pathologic changes of perineoplastic lymphatic in different stages of implanted tumor growth and lymphatic metastasis of tumor cells.


METHODS
60 Kunming rats with injection of 5 x 10(6) U14 tumor cells into each rat tongue were chosen and randomized into 6 groups. In every 5 days, specimens of rat tongues with implanted tumor and neck lymph nodes with possible metastatic tumor cells were removed from each group of rats. Cryosections of rat tongue were processed with a modified enzyme-histochemical staining technique, using 5'-nucleotidase with HE to demonstrate lymphatic capillaries. Attention was paid to pathologic change of lymphatic capillaries in perineoplastic area of rat tongue in different growth stages of implanted tumor. Routing wax sections of lymph nodes processed with HE staining were examined under light microscopy to determine whether there were any metastasis tumor cells.


RESULTS
1. Metastasis to neck lymph nodes could be observed 15 days later after injection of U14 tumor cells into rat tongue. The situation of metastasis of lymph nodes varied greatly from tumor cells in bundle within marginal sinus to complete occupation of lymph nodes by U14 cells. 2. Tumor cells penetrated the lymphatic capillary by passing singly or in clumps between endothelial cells or through some destroyed endothelia. A great number of lymphatic with dilated cavity was found nearby the tumor tissue which facilitated tumor cells to enter the lymphatic cavity. 3. There were much more amount of lymphatic capillaries with dilated cavity around tumor mass comparing with that of normal tongue of the control group rats, and the number of lymphatic capillaries with opening cavity tend to increase with growth of implanted tumor.


CONCLUSIONS
Direct and objective view of lymphatic capillaries can be obtained by means of the modified enzyme-histochemical staining technique, using 5'-nucleotidase with HE to demonstrate lymphatic capillaries; A great number of lymphatic capillaries with dented cavity in normal physical state are forced to be dilated during process of tumor growth, thus in turn increase the possibility for tumor cells to penetrate the lymphatic capillary by passing singly or in clumps between endothelial cells.
Xuan
M
M
College of Stomatology, West China University of Medical Sciences.
Weng
Y
Y
Wang
C
C
Li
X
X
D000818:Animals; D005260:Female; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D009368:Neoplasm Transplantation; D011897:Random Allocation; D051381:Rats; D011919:Rats, Inbred Strains; D014062:Tongue Neoplasms / Q000473:pathology*