Comparison of endoscopic features of early stage squamous cell lung cancerand histological findings

Seventy cases with early-stage central-type squamous cell carcinoma were tr eated surgically between 1984 and 1993 in seven participating institutes. W e classified endoscopic features of early-stage central-type squamous cell carcinoma into three types (hypertrophic type, nodular type and polypoid ty pe). After surgery we investigated the relationship between endoscopic feat ures and both the area of superficial extent and depth of carcinoma invasio n based on histopathological investigations of the surgical specimens. In 6 6.7% of the hypertrophic type lesions cancer cells did not invade into the cartilaginous layer, and only 4.8% of this type showed tumour invasion beyo nd the bronchial cartilage. On the other hand, a few nodular and polypoid t ype cases showed in-situ carcinoma or carcinoma with invasion from the sube pithelial layer to the muscle layer, and in approximately 20% the these typ es we observed carcinoma invasion beyond the cartilaginous layer, which was not suitable for photodynamic therapy, Also, concerning the greatest dimen sion 24 out of 35 lesions (68.6%) less than 10 mm in the greatest dimension were evaluated as either in-situ carcinoma or micro-invasive tumour within the muscle layer. The endoscopic features can provide a basis for the dete rmination of therapeutic strategy in early-stage central-type lung cancer.