Metastasis and cellular reaction of the cervical lymph nodes in a rabbit VX 2 tongue cancer model

Abstract

Tumor infiltration to the tongue, metastasis, and the cellular reaction of cervical lymph nodes were studied histologically in a rabbit VX 2 tongue cancer model to examine the process of lymphatogenic metastasis.
Rabbits were killed on the 3 rd, 7 th, 14th, and 21st days after transplantation of a VX 2 cancer cell suspension into the left lateral border of the tongue. The tongue and cervical lymph nodes were removed, and all deparaffininized sections prepared by a routine method were stained with hematoxylin-eosin and observed by light microscopy. Particularly, the cellular reaction of cervical lymph nodes was examined for signs of sinus histiocytosis (SH), paracortical area hyperplasia (PH), and germinal center hyperplasia (GCH).
The transplanted tongue cancer showed increased proliferation and infiltration with time; lymph node metastasis also increased. Metastasis was not always found in lymph nodes with a positive cellular reaction. However, the cellular reaction of cervical lymph nodes was already observed on the 3 rd day after transplantation of the VX 2 cancer cell suspension, and it became more marked with time. SH and PH were initially remarkable, and then GCH developed. The cellular reaction of lymph nodes distal to the tongue was weaker than that of proximal lymph nodes. It was suggested that the route of lymphatogenic metastasis can be estimated before cancer formation by evaluating the cellular reaction of cervical lymph nodes.