1. 대조군은 실험기간동안 육안적으로 정상혀와 차이가 없었으며 조직학적으로도 정상혀와 같은 사상유두가 잘 발달된 불규칙한 표면을 가지고 있었다.
2. 실험군은 10주째 사상유두의 국소적인 소실과 미약한 상피증식 및 염증세포의 침윤을 보였고 16주째만 이형성의 소견이 나타났으며 그후 큰 변화가 없다가 32주째부터 잘분화된 편평 상피암이 출현하였다.
3. 발암계와의 간접 접촉에 의해 유도된 설암은 발암제의 직접 도포에 의한 구개암보다 8주 늦게 발생하였고 암발생 기간중 육안적으로나 조직학적으로 특기할 변화소견을 보이지 않다가 32주때 갑자기 출현하였다.
4. 설암은 육안적으로는 설배의 융기부를 중심으로 궤양 혹은 외방성 종물의 형태로 나타났으며 점막 상피층에서는 사상유두의 소실, 과각화증을, 검막하 조직에서는 만성 염증세포 침윤과 많은 keratin pearl이 관찰되었으며 정상 점막층과의 이행부위를 보이면서
점막하 조직과 근육 조직내로 깊이 침윤되어 있었고 혈관내 종양세포군은 관찰되지 않았다.
[영문]Lingual carcinoma are difficult to induce than other part experimentally, thereby preventing studies of pathogenesis, biology and histology of the tumor.
The present study was to describe the gross and histopathologic changes of tongue carcinoma secondarily induced by local application of 4-Nitroquinoline-N-oxide(4NQO) on rat palate.
55 albino rats, Sprague-Dawley rain were used for experimental animal, propane-1, 2-diol for control group(15), 0.5% 4NQO solution diluted in propane-1, 2-diol for experimental group(40) were painted on the palate 3 times weekly for 30 weeks with
No.2 brush. The animals were sacrificed 2 every 4 other weeks (or control group, 2 every other weeks for experimental groups.
The obtained results were as follows;
1. In the control group, no changes were noted during experimental periods grossly and showed irregular surface due to well-developed filiform papilla histologically as nor mal tongue.
2. In the experimental group, focal loss of papilla, mild acanthosis and infiltration of chronic inflammatory cells in 10 weeks, mild dysplasia only in 16 weeks, after that, no specific change and followed by well-differentiated squamous cell carcinoma from 32 weeks observed experimentally.
3. Tongue carcinoma induced by indirect contact with carcinogen were induced in 8 weeks later than palatal carcinoma by direct application of carcinogen, and abruptly appeared in 32 weeks of experimental period without gradual changes grossly and histopathologically.
4. Grossly, induced tongue carcinoma showed ulcerative or/and exophytic patterns around the crest on the dorsum of tongue, and histologically, it was well-differentiated squamous cell carcinoma that shows loss of papilla, hyperkeratosis, infiltration of chronic inflammatory cells and keratin pearl
formation with infiltrative growth into underlying connective tissue and muscle layer. Transition focus between mucosal layer and tumor lesion, and no tumor emboli in blood vessel were observes.