OBJECTIVETo establish the deep cervical lymph node metastasis model of tongue VX2 carcinoma in rabbits and to observe its metastatic features.

METHODSThe VX2 carcinomas were transplanted into the left ventral submucosa of tongues of 16 rabbits by injecting carcinoma mass suspension. According to the time the rabbits were killed after the transplantation of VX2 carcinoma, they were divided into four groups, or 7-, 14-, 21- and 28-day groups, and 4 rabbits in each group. The specimens of transplanted tongue carcinomas and cervical lymph nodes in the rabbits were examined histopathologically after they were killed.

RESULTSAll rabbits developed VX2 tongue carcinomas at the transplanted sites, which were confirmed with pathological examination, and the mean diameters of tongue carcinomas of 7-, 14-, 21- and 28-day groups were (0.74 +/- 0.06) cm (average +/- s), (1.62 +/- 0.06) cm, (1.82 +/- 0.04) cm and (2.52 +/- 0.07) cm respectively. No cervical lymph node was palpable at bilateral necks in each rabbit of 7-, 14- and 21-day groups, and only 4 rabbits of 28-day group had palpable lymph nodes at ipsilateral necks. The histopathological examination revealed no lymph node metastasis in the rabbits of 7-day group. Ipsilateral deep cervical lymph node metastases were confirmed histopathologically in each rabbit of 14-, 21- and 28-day groups, which located beside larynx-trachea. Two of 4 rabbits in 28-day group occurred bilateral deep cervical lymph node metastases. The mean diameters of the ipsilateral deep cervical lymph nodes of 7-, 14-, 21- and 28-day groups were (0.52 +/- 0.03) cm, (0.78 +/- 0.04) cm, (0.82 +/- 0.03) cm and (1.42 +/- 0.08) cm respectively. No metastasis from the transplanted tongue carcinomas was found in superficial cervical lymph nodes and submandibular lymph nodes in all rabbits.

CONCLUSIONSThe deep cervical lymph node metastasis develops at 2 weeks after the transplantation of tongue VX2 carcinoma and a deep cervical lymph node metastasis model of tongue VX2 carcinoma can be established.